I have an RRA Varmint and the front swivel nut came loose. The sling swival fell on the shooter bench and I retrieved the nut on the ground.  I was going to take the forearm off but have never done that.  I looked through the manual RRA put in the box but it is the mil-spec "generic" manual. I surfed the web and find this to be the case for many manufacturers. They depict the "Two Piece" forearms and suggest the "Buddy System"  So how do you do it with a one piece tube forearm like on my RRA?

Edited because I didn't read your whole post before replying, oops.

The one piece handguards are either the barrel nut or the screw onto the barrel nut, so they are not easy to remove.

If the handguard is one piece you have to remove the gas tube which locks the barrel nut and possibly the front sight. Then you can unscrew the whole tube with a strap wrench or a special wrench from Brownell's which fits the holes at the back of the hanguard.

If the handguard is two piece you can unscrew the handguard part without removing the gas tube, but you'll have to remove the front sight.

I have not tried this, but I'm interested because I have a Colt upper with a one piece handguard I'm thinking of dissassembling. Hopefully someone with first hand knowlege will post.

Two piece handguard: Pull down on the delta ring, pull off the handguard. It takes a lot of force. By 'one piece handguard' I assume you mean a FFH. Dunno 'bout that.

I took the to screws out of the gas block and it wont budge. I am afraid to get a "bigger" hammer I dont want to damage anything. So I am stuck and cant remove the one piece handguard.

MTC(SS)

The float tube handguard should be a two piece unit.  What you need is a strap wrench availble at Harbor Freight or Sears.  This is one of those tools that has the rubberised strap that loops around the handguard.  Secrue the upper with a good receiver clamp if you have one.  If you don't hopefully you have a very strong friend =)  Use the strap wrench about 4" from the front of the receiver and turn the handguard off.  This is just the handguard the barrel nut should stay in place.  It should hopefully slide over the gas block once its been unscrewed. Depending on the size of the nut you may be able to get put the swivel back on and slide it back over the gas block and re-tighten it on the barrel nut.  It really isn't that hard, 5 minutes.  10 minutes if you have to remove the gas block.  and don't use a real hammer on the gas block.  A rubber mallet should do or a dead blow hammer.  

My RRA varmint is a one piece hand guard varity. The biggest issue at this point is the removal of the gas block. Both screws are out and it wont budge a bit. Rubber mallet tapping didnt help. I am afraid to apply much more force.  I am sure if I get the gas block off then a strap wrench will twist off the handguard without an issue. I tried to get Steve at RRA on the land line all this week and he must be busier then a one legged well digger. Anybody have an email address for RRA technical support. They really should get that posted on their website.

MTC(SS)