All (item #'s) correspond to the Exploded Parts View on page 11 in the Bersa Pro Series Owners Manual
How to remove the Internal Locking System (item #54):
Using the Safety key (item #53) rotate the Internal Locking System such that it is in a position between Fire and Safe on the frame.
From the opposite side push it out, being very careful not to lose the Locking System Bearing (item #55).
Once you have removed the Internal Locking System you will be able to remove the ILS Spring & Stop (item #56 & 57).
Warbird1, I'm sorry I really don't understand your questions. Just to clearify, this is not meant to to be done just to remove the internal safty system. To defeat it. It's meant to use as a set of instructions for the complete take down of the frame, or to replace that part if it is broken.