Magazine latch and latch thumb piece removal (Apache 77). The Service Manual says to remove both the latch and guide at the same time by removing the guide screw. The guide screw (small machine screw, flat tip) is directly under the latch thumb piece and completely and totally inaccessible. Service manual says to remove the thumb piece from the latch AFTER removal from the gun. Can't be done. How do I get the thumb piece off the latch WITHOUT removing the magazine guide, latch, and guide screw?