What year?
This is what I do.
Raise the front of the car and support it with jackstands.
Remove the wheels.
Remove the caliper and hang it inside the fender well someplace. Don't let it hang by the hose.
Pop the tie rod end loose from the knuckle.
Remove the shock absorber.
Remove the rotor and set it aside. (If you have an 84-87, the rotor is part of the hub. You can leave it attached to the knuckle, but it may be clumsy to deal with.)
Place a floor jack under the lower control arm.
Loosen the lower ball joint nut by about 1 turn.
I use Rodney's ball joint separator tool to push the ball joint stud loose from the knuckle. Since the nut is only loosened by one turn, it should pop loose with a bang, and then be held by the nut.
Make sure the jack is supporting the lower control arm, and remove the nut.
Lift the upper arm and knuckle up and out of the way. Prop it to stop it from falling. OR you can remove the upper ball joint and upper control arm from the knuckle in the same manner as the lower, before you remove the nut from the lower, and set the knuckle aside.
The lower control arm should now be free to pivot on the bushings, but still supported by the floor jack.
It is recommended to loop a chain or cable through the spring to keep it from flying out when the LCA is tilted down. The springs are under a great deal of pressure and can really mess up your day if they fly out.
Once the spring is secure, slowly lower the jack from under the LCA, allowing the spring to expand. At some point the spring should be able to be pulled free of the control arm, and removed. You might have to use a pry bar or a big screwdriver to pop it out of the cup on the LCA.
Assembly, as they say, is the reverse of disassembly.
Edit - Dodgerunner beat me to it, with a lot less verbal diarrhea.
Good luck.
[This message has been edited by Raydar (edited 11-08-2013).]