Benelli M1 Super 90 tube

How does anyone get this tube off for cleaning or changing the spring?

It's one piece. Doesn't seem brazed to the receiver. The blow-up diagram on the manual suggests it unscrews, but I can't budge it.

Advice?

(I am not a gunsmith--beyond dropping in replacement parts and occasional detail stripping of guns I know, I tend to leave things alone).

Unscrew the nut at the front of the mag tube and you can remove the spring and follower and clean it too! No need to remove the lower mag tube, just the nut and/or extension

Just watch it, theres a lot of pressure on the spring, moreso than most shotguns IMO

LOL! Shot mine across the room my first time !

No nut or screw at the front of the tube (? older model), no extension link--the tube is rounded over in front. Only point of attachment is where tube meets receiver.