Learn to fit a new car lock

First get access to the car. Then access the door; with a screwdriver and pliers remove the door panel and the handle that is held by some screws. After that locate the old rod and take it off.

Now you will easily remove the handle. Keep the old pieces until the end as you can’t know what you will need.
The lock is held in place by a clip and a snap ring. So what it remains for you to do is fix the lock in place and secure the ring around it. You must know that it will stay in place only if there’s not much movement around it.
In the end reinstall the handle at its place. Then do the same with the inside handle. After you do this, you can put back the panel on the inside. This is a job for you and a partner that must hold the panel in place while you do the rest. You need to make sure that every screw is back in its place as well as every other piece.