A bulk of the work in lowering the newer GM fullsize happens up front. When we arrived at the Drop Shop, the staff had already gotten underway by blowing off the lower A-arm. To get the coils out and the arms off, support the frame independently; compress the lower A-arm using a floor jack and the weight of the truck. When the suspension compresses, loosen the lower ball joint nut and beat the heck out of it with a dead-blow hammer. After the ball joint has separated, removed the nut and lower the jack very slowly; the coil should literally fall out. Next remove the lower A-arm bushing bolts and get that puppy face-up in a bench vise.