I can't get it apart!!! I don't know how to get the barrel off. I get the magazine extension off, and the spring out, but I can't get the barrel off. I do what the instructions say, and slide the fore-end halfway forward, but the barrel won't budge. It seems like the part that the magazine extension threads into (the magazine tube coupling, as the owner's manual calls it) needs to come off, butt I have read online that that stays on the barrel. Can anyone verify or deny this? I'm starting to thing it might just be stuck because it's brand new.