My AR has a free float rail on it but I want to put a delta ring and stuff back on, what all do I need to buy and do?
Upper receiver clam shell or receiver block.
Barrel nut wrench
If you free float doesn't use a standard barrel nut, you will need a new one.
Remove BCG and charging handle.
Remove gas tube
Place receiver in block or clam shell.
Use barrel nut wrench to loosen the barrel nut.
Once loose remove the barrel.
Remove the flash hider then the gas block or front sight base.
If it's a aftermarket barrel nut, then remove that and put a stock nut on there.
Put the delta ring over the barrel nut. Then the weld spring, then put the snap ring around the groove on the base of the barrel nut.
Put the barrel back on and tighten down the barrel to 30ft/lbs. Then loosen and do it again, then loosen and do it again (a total of 3 times)
Tighten it down to 30ft/lbs again and align the open space between one of th teeth so that the gas tube can be slid through to the upper (up to 80lbs if necessary)
Align the Delta ring gas tube opening with the snap ring gas tube opening and weld spring opening.
Put the hand guard cap on the end of the barrel with the dished side facing the receiver.
Put the gas tube into the receiver with the rest of it on the barrel
Put the gas block or front sight base on.
Attach the gas tube to the gas block or front sight base.
Put on handguards.
Also see How to assemble a upper/lower/free float
For starters, you will need a standard barrel nut if your current forearm uses a different one. You will also need:
-end cap (round or triangular)
-2 piece handguards (standard, MOE, railed, whatever floats your boat)
For tools, you'll need:
-upper receiver vice block/ jaws
-barrel vice jaws
Basically, you will be disassembling and reassembling your upper to do this. Unless you have a clamp-on gas block, you will have to remove your flash hider in order to remove the gas block or FSB. In this case, you should buy a new crush washer as well. This is where the barrel vice jaws come in. Its not a good idea to put that much torque (removing/ torquing a flashhider) on the barrel extension pin.
Once your muzzle device is removed, you can slide your gas block off of the barrel. If you have a pinned gas block or FSB, the brass drift should help when removing and installing the taper pins. A set screw or clamp-on gas block should be easier to remove. I'm pretty sure that you can get away with leaving your gas tube in the gas block. If not, you'll need to drift out the gas tube roll pin.
The armorer's wrench is used to remove the barrel nut. If you have a standard barrel but, do not remove it.The pins in the wrench fit into the boles in the barrel nut. Righty-tighty/ lefty-loosey. For this part you'll need your upper receiver secured in a vise using an upper receiver block or upper receiver jaws. I've heard that barrel vice jaws can be used for this part as well, but I've never tried it.
Grease your new barrel nut and torque it to 30-80 ft-lbs so that it indexes with the hole in the upper receiver. If your gas tube slides in easily, it is indexed properly. You don't want you gas tube cocked to the side, especially with the gas key slamming home around it. Slide the handguard end cap down the gas tube so that it touches the gas block, then slide the whole works down the barrel and secure the gas block in whatever way it is meant to be.
Reinstall the muzzle device. Enjoy.
There are several videos online that show the barrel installation process. I'd suggest watching a few. Its really not that hard to do, as long as you have the right tools. It just sounds like a lot.
Edit: I wish this forum had a "someone is already typing a response" feature. That was a lot of words for me.
I'm sure that question has been asked a thousand times, thanks for taking the time to answer it for me, it helped me a lot. Now time to go buy some tools so I can do it. Thanks again.