Benjamin Sheridan Soldered Valve Repair Instructions 1. Remove stock assembly from action/barrel assembly by removing the receiver stock screw #12. 2. In order to replace the rubber piston head #5 you must first remove the piston rod assembly #5. To do this, the roll pins #2 must be tapped out and the muzzle cap #1 removed. Now, you can line up the pin holding the pump handle in with the roll pin hole and punch that out too #4.