I have a standard 16" J&T barrell with CAR length handguards and an A-2 front sight post.  I also have a free float CAR length tube and 4 rail pictanny gas block that I would like to install.  Can someone briefly explain how to install these items?  Tks

Upper in an upper block vise, vise in tight.

Remove the gas tube (roll pin), and then loosen the barrel nut to remove the barrel from the upper (pull straight out).

Remove the front sight taper pins by driving the pins out of the sight (drive them out from the small side).

Remove the front sight tower, then the complete delta ring assembly (barrel stripped down to just barrel and barrel extension)

Put the stripped barrel back in the upper, then slide the barrel tube nut section down the barrel and tighten to 35 inch pounds (down three times, then a little more to align the nut top hole with the upper gas tube hole to allow the tube to pass threw the two).

If the hand tube will fit over the new gas block, then install the block (paying attention to align the gas port holes on the block/barrel, then tighten the block using the bottom set screws in the block.

Install the gas tube, and then check the tube alignment in the upper when the carrier key slips over the tube. If needed, slightly bend the tube at the middle of the barrel to align the gas tube correctly in the upper.

Install the outer sleeve of the gas tube with a band wrench. Before you attempt to install any type of after market lugs/attachments to the tube, fire at least 200 rounds threw the rifle, then retighten the outer tube once more.  This will make sure that tube is tight, and will not rotate over time, making any attachments added to the outer tube out of the desired alignment if the tube loosens as it breaks in.

Thanks Dano.  Thats the kind of response I was hopeing for.