Barrel swaps are pretty simple, but you need some tools: a
bench vise, an upper receiver block, a small punch and hammer, a barrel wrench, and a 1/2" drive breaker bar and torque wrench. Some grease will be good too; I use synthetic high temp wheel bearing grease (the Valvoline SynPower stuff, specifically). Pull the upper off, remove the BCG, charging handle, and handguards. Tap out the ...