1. Make sure you purchase the correct replacement lock at your home improvement store. This one looks like a match.
2. Before removing the old lock or installing the new lock, insert the long door handle screw in the door. Now it is safe to remove the two mounting screws located on the face of the lock.
3. Failure to perform step #2 above allows gravity to cause the lock to fall down inside to the bottom of the door. Not such a big deal if it’s the old lock being replaced, such as in my case, but you don’t want to drop your new replacement lock down there. As far as I know, there is no easy way to retrieve it without removing the door. Notice my new lock stays in place while I go grab the two mounting screws.
Well that’s it. I hope I was able to save you that 2nd trip to the home improvement store.