Replacing a broken or seized window lock is as important as replacing a door lock for your security, which is the reason we offer the same fast, quality window locking mechanism and handle replacement service our extensive range of replacement parts and materials means we will be able to resolve any window lock problems you have quickly and efficiently. In many situation where your keys are lost, stolen or broken, we can get you in your property very quickly as we are very experienced, 90% of the time there will be no damage to your door or you will need a new lock and key we only damage doors when locks fail or its a very high security system. This thread is closed, therefore you are unable to respond. When replacing a lock you need to use a master key which you can order below the first step will be to unlock your current lock, if you are replacing a lock for a roof box, you need to position the key diagonally between the locked and unlocked position take out your key and insert the master key now you are able to slide out the old lock and place in the new one.