Any tips for getting the threaded tube inside the pump fore end off on a remington 7600? I have one here that has never been disassembled and needs a proper cleaning. I've watched the videos and read through some forums. I have a proper takedown tool that engages the 4 little cross holes instead of a screwdriver or punch like most people seem to use. It still won't budge though. I read there may be loctite on that stud. I've tried oil and brake cleaner so far, but not heat. The rifle is in really great condition, aside from the old gummy oil and such, so I'm trying to be extra careful not to mar or gouge anything up...