I have an old Crossman 140 air rifle. I am looking to clean it up and have a little fun with it. I am looking to remove the wood fore end on it to refinish. It has what looks like roll pins that come in from one side of the wood and go thru the "U" shaped metal arm that pumps the gun. They only come in from one side so they can't be punched out. The "U" shaped groove is about 1/4" or so. Any suggestions?? Thanks.