*HOW TO REMOVE THE GAS TUBE COVER* and remove top hand guard
The unlock lever is just rear of the top hand guard and gas tube. Remove the dust cover, disassemble recoil spring and carrier. Rotate the gas tube lever until it is perpendicular the top hand guard and gas tube can then be removed. Holding the flats with a crescent wrench merely rotate the hand guard 180 degrees and lift out.
I just found out how to do it and thought I'd share with the other new guys.