There's a special spring compressor tool that slips up through the center of the coil once the shock has been removed. Yeah, the external ones are hopeless.
Looking at mine, this is how I would do it without that tool.
This is a little dangerous. The spring can squirt out in a hurry if you're not careful.
Assuming the knuckle is already off, set the crossmember on a jack stand. Jack up near the lower ball joint (should actualy have a little shelf welded to the lower arm for this very purpose) and take out the shock absorber. Unhook the sway bar. Set another jack stand near the ball joint and remove the jack. Now jack up on the whole control arm directly below the spring perch. Remove the second jack stand and pivot bolts and lower the jack, bringing the arm down with the spring.
Use a floor jack, not a bottle jack since it's more stable. Thread a chunk of wire rope through the spring and secure it to the frame so if everything goes wrong it won't get too far. You could also probably reconnect the knuckle temporarily to limit how far stuff flies.
There are two little holes in the lower arm. The spring needs to be installed so the end of the coil covers only one hole.
And remember to have the truck's weight sitting on the suspension before tightening the pivot bolts.
Welcome Visitor! Please take a few seconds and 
