i bought a s&w 15-22 in september, and loved and had to buy a "real" ar15. last week i picked up my DPMS carbine with 11.5 barrel and 5 inch flash suppressor. it has a A2 upper reciever and A2 front sights, and a standard round handguard/float tube.
i would like to switch out the A2 upper to a Flattop Upper, the A2 front sight to a gas block either smooth or with rails, and the standard handguard to a 4 rail
my question is what tools will i need to do this and how do i swap out the upper reciever and gas block???