Yondering wrote:
Disassemble the frame and look inside at the area you're wanting to remove material from - you'll see there isn't really any room to remove much more than just the texture. The SF frame and gen 4 frames use a different ejector housing to make room for the shorter front to back distance at the web of your hand compared to the gen 2 and 3. Best of luck; honestly your best move is to sell it and buy an SF or gen 4 that fits your hand.
About the only area you can really remove material or change the grip shape significantly is below the ejector housing pin in the backstrap; that area is hollow and can be modified.
I second what he said. The finger grooves are easy. Smoothing the sides is about all you can do.
Some people have filled in the hole and reshaped it, but I don't think there's any way to guarantee that the filler material will hold for sure over long term use.