The FM hi power is a Brazilian copy of the FN hi power. Not all parts are interchangeable.
I suggest you do a search on the FN high power to learn more about your pistol. If you do anything make sure the pistol isn't loaded.
Are you sure your Dad doesn't have an instruction manual for it?
On a personal note I try not to dry fire any pistol that I own (old school)
Nice gift, but be careful.