(repost from Pistons Forum)
so I got an Adams Arms XLP Gas block (with drive rod spring, and bushing) on the way, and a Midwest Industries Rifle Length Gen II 2 piece FF rail to go with it.

So I'm going to yank the existing gas block of of my S&W M&P15, take off the Delta ring and attach all this stuff and head to the range.

so, got those of yall who have messed with DIY Piston systems or a rail that required the removal of the delta ring, do you have any tips (particularly for removing the delta ring). Also, what kind of tolerances am I looking at trying to attain?

I've worked on M4's before, but this is a new level of fun for me, since I've never really mokeyed around with the slip ring, and I'm like a kid waiting for Santa right now.

Have to remove the barrel nut first. And then dissaemble the delta ring assembly. (I use two pin punches and another object to use as a pivot point to get the clamp ring off.)