What is the  procedure to instal an aluminum freefloat hanguard on my A2 upper?

Pull the barrel, then pull the front sight tower to remove the barrel nut off the barrel.  

Slip the bare barrel back in the upper receiver socket, install the tube barrel nut(index to allow the tube to go threw), then the  float tube, then the front sight tower, and gas tube.

I am interested in doing this also, on my Colt Comp Match HBAR.  I am a rookie, and that sounds too simple! :)  Is there a detailed link, maybe with pictures, to refer to?  Special tools needed?  I have searched the web but probably not well enough. Thank you.

It's not that simple. The Gas block can be a pain. and so can the barrel nut.

it is pretty simple.  just make sure the handgaurd is short enough to fit the site back on and tall enough to cover the gas tube.  when putting the new barrel nut on, line up one of the holes to the hole for gas tube in the receiver.  and it might be easier to leave gas tube in the site when remounting.  just one question though, why??  its not my rifle but my opinion is this will not look good.  save up and buy a nice bull barrel and get rid of the front site.  but thats my opinion.  if ya need any other help feel free to email at   [email protected]

Thank you for the reply, and more detailed explanation. From what I hear there is more accuracy potential with a float tube than the current handguards. I can't afford a whole new upper, and not sure what it takes to replace a barrel (let alone do the float tube).  I have seen some nice looking options, so I hope it won't hurt aesthetically. A fairly simple project like this might cause me to catch the AR upgrade bug, and learn a little more about my Colts in the process.  

I've got a few pictures of the process if you have a specific step you want a picture on.