I've seen on the EE a couple of 1-pc freefloat tubes. I've never seen one of these in person, but I assume the tube is also the barrel nut? You install it with a strap wrench?
Some are one-piece units that you do install with with a strap wrench. Others are two-piece units where the rear-most part of the tube is actually a seperate barrel-nut that threads onto the main body of the tube after you tighten it to the receiver with a conventional barrel not wrench. The latter is much easier to install; particularly when lining up the gas tube hole.
I would look at the brand name of each unit and then find a website for whomever manufactures and/or sells that particular item.
I was told by Hogue that you punch out the two pins on the front tower site slide that off and slide on the new one piece forend and re-add the gas tube ??
It difficult to tell via the manual and tear downs I've read.
I read there was a nut to remove or losen but wasnt sure.
I would have to buy the tool to remove it.
Does the nut go behind the front site or back where the butt of the barrel inserts into the upper ??