Depends on what you have for tools but I remember rigging something up in a vice to remove a stubborn trigger pin before that could not be beat out. All I used was a drill, a piece of hardwood, and a hard steel metal rod the right size.
I removed anything that would cause interference like the grips, slide, and safeties I put the piece of hard wood in the vice and the gun up against it. You will need to drill a hole in the hardwood where the trigger pin is going to come out. Last thing to do is line up the other side of the vice with the short rod and trigger pin whole and start tightening. After you move the pin a little it will probably come out by hand.
Also it wouldn't hurt to have another pair of hands to help hold everything.