I have a CG X-treme mod 22 in an Eliseo Tube Gun w/ a Pierce action. I want to lighten the 2nd stage and I believe (per Tom Meyers) I need to access the #4 screw. What is the easiest way to gain access to this screw? I believe it is on the top of the trigger. Is there an access hole through the tube action sleeve? Do I have to disassemble the rifle?