Hmm, let me see if I can remember all this, and furthermore make it ledgable. I learned how out of Brownell's Encyclopedia of Modern Firearms, Volume 1: Parts & Assembly.
Clear the gun and leave the bolt open (otherwise the extractors will prevent removal of the barrel.) Screw the magazine cap on to the magazine tighter so the little stud on the front will dissengage the barrel lug. After the cap is screwed on all the way tight rotate the barrel 90 degrees counterclockwise (as seen from the muzzle end) and pull the barrel out. After the barrel is removed you can unscrew the magazine cap and remove the follower and spring from the tube. Now look inside the feeding/ejection port at the bottom of the bolt (the slide actually); there is a crosspin with a groove in it that allows you to pull it to the side. Use a slot screwdriver to push it to the right side of the gun (now the left side since the gun is upside down. Basically just push it away from the action bar.) This dissengages the action bar and allows you to pull the forend off of the tube.
Push the bolt/slide all the way to the forward position and dryfire the gun. Remove the trigger group screw (left side above the trigger) and pull the stock to the rear; the trigger group will come out with it. As the trigger housing clears the back of the receiver, pivot the stock up so the hammer will clear the shell carrier. After the trigger group is gone, the right-side shell stop can be removed (read: will probably fall out anyway.) The left-side shell stop shouldn't be removed from the gun.
There is a screw on each side of the shell receiver holding the shell carrier in, and each of these (weird looking) screws is held in by another, smaller screw. Remove the small retaining screws, then remove the large funky-lookin' pivot screws. Finally, pull the shell carrier, bolt, and slide out of the rear of the receiver all at once.
Reassembly is the reverse of dissassembly, just remember the bolt has to be open to insert the barrel, the barrel goes in with the locking lug on the left and rotates to lock, and the magazine cap is backed off of the tube in order to hold the barrel lug in place. Oh, and don't forget to put the shell stop in when you reassemble, like I did the first time.
