In an old thread someone reported second-hand that it's held on by silicone and can be twisted off, but that was absolutely NOT the case with mine. It's quite solidly welded on. I couldn't even get it loose using a propane torch.
So you have to go through the barrel shroud vents to remove the tab holding the stock onto the shroud, which is what I assume you're trying to do. Yes, the inner barrel's in the way, which means you have to remove the grip and remove the trigger group, revealing a couple of small philips-head screws. Remove those screws and the "bolt" will loosen, enabling you to let it and the barrel slide back into the tube. Beware that there are screws going into the tube from the inside of the mag well that will scratch up your bolt as it slides around if you're not careful.
By the way, I was unable to find a way to loosen the stock without permanently removing that tab, meaning that I had to come up with a new way to make the stock stay stuck to the shroud. I used a snap.