i used this title in the search function and was unable to find any info for the topic, soooo…!
what is the best method for removing the gas tube from an AR without damaging it after removing the roll pin ?
as many of you know the tube is damn near “welded” in after a few hundred rounds, i like changing configurations and often run into needing to remove the gas tube.
suggestions and ideas welcome.
There’s a Brownells tool for the job.
Just curious. What type of configuration change requires often changing of the gas tube? 
I bought a gas tube puller about 10yrs ago.used it 2 times.I guess I finally got my money back.
When you buy Ned Christiansen’s MOACKS, it comes with a gas tube clamp/removal tool.
Plus one on the gas tube removal tool available at brownells if you really dont want to damage your old one.
I cant really think of a guaranteed alternative if you dont want to spend additional on a tool that you will rarely need… maybe you can use a vise grip and gently clamp it on … but if as you said its “stuck”, I think its either you spend on the tool or a new gas tube. 
I usually remove the FSB and gas tube as one unit, unless replacing the FSB with a different gas block. This has worked well for me.
That being said, the tool I saw from Brownells would pay for itself if it saved you a couple of gas tubes.
-RD62
changing barrels, uppers and anything requiring gas tube removal 
I find a tool for this task is rarely needed.
I’ve never even removed a gas tube so I really have no need for this tool!
The last one I did I soaked it in Break Free, wrapped some electrical tape around it, and lightly clamped vise grips to it. It took some patience and a little luck but it came off without damage.
I realize that. Most people change the upper receiver assembly and don’t pull their barrels and tubes when they want to change the configuration. If I pull a barrel and the tube looks ratty I replace it in which case I just cut the tube and yank it out.