Gearbox out of the body of the AUG? After field stripping it, you have to remove the rear plate, remove the battery plate and then actually *bang* (yes, BANG) the bottom of the AUG until the gearbox falls out the back. I have taken apart 3 AUGs and this is even the way that retailers like AirsoftExtreme tell you to do it. Whatever you do, do NOT take the body apart on the AUG.