Bruskie - Welcome to the Journal.
Several makers of vises use the pin method to hold the jaws in place. I measured the rough size of the pins that needed to come out. Then I went to Sears and bought long style pin punches....one that was the size and one that was just undersized. The pins are just a mild steel pin usually and there aren't any tricks that I know of to remove them. Just get a slightly heavy hammer and have fun. Don't be surprised if they come out in pieces. Now...let's say that they just aren't coming out. You can (and I say "can") take said hammer and hit the jaw insert from the side...hard. Do it on both sides and you will break the pins internally...shear them. It can wallow the holes and do things that you don't want to happen...but I have done it once or twice when a pin will absolutely not come out. Good luck and let us know how it goes.
Craig