I have a SAA made in 1906 and someone had cut the pins flush with the frame so appearently they had a set of one one piece grips at some point. Fortunantly, they did not "Bugger Up" the frame. I removed the two piece grips and clamped the frame to a Polypropolene Gunsmithing Disc and tapped the pin out. It took a few hard hits, but came right out. I checked the diameter, and the pin is .135 dia. Of course, I did not have a pin the correct size so I used a .125 broken drill bit, cut to correct length, and put a small piece of masking tape to hold it in place. This worked fine while I had correct pins ordered. When the new ones arrived from Midway, they meausured .135 dia. too. They tapped in quickly with a plastic head hammer and I am good to go now. So you should not have any problem removing the existing pin.