A Simple DIY Tutorial on How to Change a Door Lock

Did you just move into a new house? How do you feel about its security? Maybe some security cameras can do the trick. But what else can you do? Whether you lost your house keys or you parted ways with your roommate, you need to change the locks. You have no idea how many copies of the keys are floating around, and changing the door lock will help you secure your home from any intruders.

Key in doorlock of apartment

Your home is your sanctuary, and this safe place is only as secure as the locks on the doors. Don’t know how to change a lock? We are here to help! In this article, we will tell you everything you need to know about changing door locks. And if you want to give your door a complete makeover then you can also give it a splash of paint afterwards! Without further ado, let’s get started!

What you should know before changing your door lock

Changing a door looks more complicated than it actually is. All you need are the right tools, the correct instructions, and just a little bit of technical understanding, and you will be changing locks in no time.

There are a few things you should know before changing your lock. Let’s see what they are.

1. Replacing vs Rekeying 

There are two ways to change the locks on your door – Replacing or rekeying. When you replace the locks, you remove the existing lock and then install a new one in its place

When it comes to this, you realign the springs and pins inside the existing lock to match the lock to a brand new key

2. Get secure door locks

Hand entering password code on smart lock

The door security of a lock is given by its ANSI grade, with Grade 1 being the most secure and Grade 3 being the least secure option. We recommend that you go for Grade 2 locks as they have anti-pick mechanisms installed in them and are relatively affordable as well. You can get smart locks as well, which come with a keypad and a code instead of old-fashioned keys. 

3. Consider getting one key for all the locks

Having a lot of keys on your keyring is not only annoying but will cost you a lot if you lose the keyring. Plus, having to fumble through half a dozen keys while trying to unlock your door isn’t fun either.

A single key that fits all the locks on your house is a blessing in disguise. As long as you have the locks of the same brand, you can rekey them and use a single key for all of them.

Types of door locks

There are various types of locks. The most common types you will find in houses in the UK are as follows:

1. Deadbolt locks

They offer the best protection when it comes to burglaries or break-ins. Their unique locking mechanism ensures that they can’t be opened by battering, boring, etc. Moreover, they can’t be opened with knives, hand tools, or similar items. 

There are two common types:

  • Single cylinder
  • Double cylinder

The single euro cylinder locks are the simplest, and you can activate them from one side through a key. You can use a double cylinder deadbolt using a key from both sides. 

2. Mortise locks

Most of the external doors have mortise locks on them. They are rebated into the doors to give a clean, flush finish. There are two types of mortice locks:

New sash lock and parts ready to be fitted to a house door

  • Sash Lock: They usually have a latch and a bolt and are used for side entrances, back doors, etc.
  • Deadlock: They come with a bolt and are commonly used on front doors

3. Knob locks

These are the most common types of locks you will find. In knob locks, the lock cylinder is present inside the knob instead of the doors. Therefore, you shouldn’t use knob locks on external doors as they can be easily broken using a hammer or a wrench.

There are rim cylinder locks, consisting of a night latch on the inside and a key cylinder on the outside.

Planning and preparation of the project

If you already know what kind of lock you’re going to use, then let’s dive into the whole planning and preparation process. 

1. Measure for the replacement lock

You need to measure the space where you will install the replacement lock. Firstly, measure the diameter of the holes that are currently present in your door and select a lock that will fit those dimensions.

If you need to enlarge the existing holes, you can do that with the help of a hole saw set. However, we recommend that instead of doing this, simply take the measurements carefully and find a lock that fits.

Also, measure the distance from the centre of the door hole to the door frame. This measurement is called setback. Buy a lock that has the same setback. You also have to measure the thickness of the door.

2. Match the key

If you want a single key for all your locks, you will have to match the key. If you are changing all the locks, you can match the keys using the key code of the back of the packages. If you are changing only one lock, you can choose one compatible with your existing key.

Step-by-step guide: How to change a door lock

Instead of hiring an expensive locksmith, you can change the door handle locks on your front door, garage doors, etc., yourself.

Things you will need

Step 1: Remove the Door Knob/Deadbolt

The first step is to remove the screws from the doorknob. Make sure to do that both on the interior side and the exterior side of the door. This will allow you to pull the door knobs off from both sides.

Next, remove the screws present on the face plate on the edge of the door. Remove the latch from the door opening. You might have to cut or enlarge the door latch plate. Place the new latch into the opening.

Make sure that the tapered side of the latch is in the direction you will push the door while closing it. The new latch plate should fit the recessed area and should be flush with the door surface.

The steps for removing a deadbolt are the same. You have to remove the screws that hold the deadbolt together from the inside. Then, move on to the two screws present on the edge of the door and simply remove it.

Step 2: Install the new lock

Knob Locks

A spindle is a long piece of metal that sticks out of the exterior knob. Install both doorknobs by sliding the spindle via the slot present in the latch. You have to align the long screws from the inside knob to the cylinders present on the exterior knob and then tighten them.

Install the new strike plate and then open and close the door several times to ensure the latch properly aligns with the strike plate.

Deadbolt Locks

Place the new bolt into the opening on the door’s edge. Fasten it using the screws that come with it. There will be an opening in the centre of the bolt. Feed the long metal piece through this opening to insert the exterior part of the lock in place.

There will be two long screws that come with the interior door plate. Insert the screws into the screw holes that are present in the bolt from the interior plate to the exterior side of the lock.

Tighten the screws using a power drill or a screwdriver. Place the decorative outer plate over the bolt. 

How to rekey a door lock

As new homeowners, you can rekey your locks instead of replacing them. Simply get a rekeying tool kit from your local home improvement store and follow our instructions. 

Door lock installation using screwdriver

Things you will need

DIY steps

  1. Insert the wire tool into the knob keyhole to pull the knob clip off the door. 
  2. Pop off the knob sleeve and remove the euro profile cylinder out the back of the knob assembly. 
  3. With the help of the special retainer ring tool, take off the retainer ring. Keep the ring aside, as you will need it later.
  4. The main step is to remove the cylinder plug. Insert the old lock key into the cylinder and turn it to the left or right. Push the plug follower through the cylinder and remove the plug. 
  5. Make sure that you are keeping constant pressure on the plug follower until you completely remove it. 
  6. Throw out the old pins and insert the new pins. To match the pins with the colour code, you will have to use tweezers or nose-pin pliers.
  7. Once the pins are in place, reassemble your lock by reversing the stepsSecure door lock


Lovers have a change of heart, roommates go crazy, and the house keys get lost or stolen. You can’t control all these things, but you can certainly change the deadbolts on the doors and ensure no one comes into your place without your permission. Instead of getting hiring a professional, you can simply change the profile cylinder lock on your own. Hopefully, you have learned how to change a door lock in this article and will no longer have to worry about your safety and security. 

Coming up next: How to fix a loose lever door handle.

Stay safe, folks!

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