My son's buddy just picked up a Mossberg 1000 in mint condition, but there's no owners manual, and he/we can't seem to break down the action to get the bolt out. We can, of course, get the trigger group out, but would like to remove the bolt and gas piston, and spring inside the mag tube for cleaning. Any help would be appreciated.. As an afterthought, I believe the gun was also made/imported by S&W, also known as the 1000. Gun was produced by Howa. Thanks in advance for any help...