For Rescue PA:
When you get out of the hole, you go up the ramp, then down...Punch out the guard (not the one standing by the door, the one that should be halfway up the ramp/maybe all the way up), pause, get out X-ray and Superdragon. Now when you go down, facing the left side, do like YE does in his 2:54...kill that guard, moving in towards him, and do NOT stop shooting as you continue down the ramp. Shoot until your gun reloads, and the guard will be at the door, with it open, every time for me. It works very consistently.