Here are some hints to make the job as simple as possible. If you are only replacing the springs then you don't want the axel to move out of place in a way that creates extra work. First jack up the front and place the frame on jackstands. At this point I like to try and rock the vehicle to make sure it is very stable. Now, using a floor jack, put very light pressure on one side to relieve the tension on the spring bushings. Next, remove the pin at the end with the shackles. This method prevents the axel from swinging into a new position on the shackles. After undoing both ends of the spring, support the axle so you can proceed on the other side. It is helpful to limit the amount that the axel drops away on the first side. If it is lowered on the one side and produces a significant cross angle it will make the second side more difficult to deal with.