Hey 6BT
As a couple of other guys pointed out here, no compressor needed. Before you start, it's easier if you completely loosen the shock stud nuts and disconnect the swaybar to begin with. (If you do not disc. the swaybar, you'll end up with the end-links all bent up and spring will not come out - yes, it is scary that I know this. )
From this point, you want to end up with the front of the truck raised as high as possible on jackstands under the frame, with both front wheels removed. You will be truly amazed at how far the axle will droop with swaybar and top of shock disconnected!(+/- maybe 18 inches)
Once you get to this point, you'll need to remove bottom shock mounting bolts. Spring may come out at this point with just a few good tugs. If not, use a bottle jack to push down slightly on the axle - there is a flat where the control arm attaches to axle and an unused bumpstop bracket on frame which makes this easy. Just watch the brake line & it is fine - I had to do this myself to install my springs when adding the 2" spacer.
Good luck,
Mike