Use the Requirements Already - I am working on a release at work. Initially we were supposed to replicate some bunch of database tables that the customer had in an old system. We did a ...
This is a subset of what's known as impressioning. Like with rake keys, you start with a key blank. Then you use the lock itself to get information on how to modify the key to fit. You will need a file to carve the key. You will also need a magnifier to spy on the lock you are trying to bypass.
You should have a couple of key blanks if you are trying this technique. You should also have something to hold the key steady like vice grips. You put the blank in the lock and turn it. The marks on the key indicate how you should cut it.
You can color the key with a sharpie to see where the lock interacts with the key. Or your could use ultraviolet rays to do the trick. The goal is to produce a real key that works in the lock.