You will have to remove the magazine tube to replace the spring.
Completely diassemble the shotgun first.
Then set the receiver in a padded vise, you will need both hands free.
Some early tubes are staked in place, you will see the punch marks around the junction of the tube and the front of the receiver.
If it is staked you will need to grind these down slightly.
A Dremel Tool with the round point dental burr works well for this.
Some tubes are secured with a Lok-Tite type adhesive and you will need to heat the receiver/magazine tube junction to break the adhesive bond before you attempt to remove the tube.
A regular propane torch will work for this, 450 degrees is enough to break the bonding material.
If you have a real early gun the slide bar may be staked to the tube and the only way to get it off is to unscrew the magazine tube.
everything below applies to these guns to but the strap wrench will have to be place farther up the tube and more care used during removal so you don't bend the magazine tube.
If you do bend the tube, replace it with a current non-staked version and forget the whole thing ever happened.
A smaller size rubber or fabric strap, strap wrench is the best tool I have found for pulling these tubes and Brownells offers several very good gunsmith quality strap wrenches that will work beautifully.
Sprinkle a little powdered rosin on the tube and strap for even better grip and less chance of marring the tube.
The tube screws off counter clockwise when looking down the tube towards the front of the receiver.
Once diassembled clean the tube threads and receiver threads with triclorothane(sic?) or any good metal preperation cleaner.
Replace the spring with a stainless steel version available from Wolff and a couple other suppliers, this is a job you won't want to do to the same gun again and the S.S. springs seem to last and last even when the magazine is kept loaded for extended periods.
I usually replace the plastic follower with an aluminum version that is also available from Brownells.
They can be had in a number of long wearing anodized colors including black and matted natural finish.
These aluminum followers will never break and seem to improve functioning by keeping the shells absolutely straight in the tube.
Again, you won't want to do this to the same gun again so why not make it bulletproof while you are under the hood.
The orange and green colors are the most requested by customers but I prefer the red, anyway,,,
Lightly coat the tube threads with Lok-Tite 609 thread retainer and insert the spring and follower and screw in hand tight.
There is a follower stop machined into the receiver so the follower isn't going to shoot into it and this also gives you a reference stop for the magazine tube.
When it bottoms hand tight, give it a quarter to half turm maximum with the strap wrench, reassemble and you are done.
It actually takes less time to do this than to write the instructions if you have everything layed out and ready to go. HTH
