I just did this over the summer, and it was an absolute nightmare... Until I figured out how to do it. The first side took me 3 days, the second side took about 1.5 hours.
A couple things first... I tried every type of spring compressor (except the ford tool), and simply couldn't get ANY of them even CLOSE to working. I tried bending the spring with both the inside and outside types of compressors, no luck. As far as the correct Ford tool goes, it's expensive, and I understand that due to the length of the tool, it will not work if the car is on jack stands. I was told it has to be used when the car is on a lift, as it sticks too far through the hole in the bottom of the control arm. Do yourself a favor and forget the spring compressors.
Like bubbah, hissin, and fiveoh already said, leave the control arm attached to the shock, and unbolt it from the K-member with those two bigass bolts. At that point you can drop the arm WAY down and set the spring in there. People suggest that at this point, you use two bottle jacks to raise the control arm (and compress the spring). I didn't have two (or even one) bottle jack, so here's what i did:
Take your nice big hydraulic floor jack (probably won't work with one of those tiny $20 specials) and set it on two 2x4's laying flat, just to get the wheels off the floor. This method won't work if your jack is rolling around. Then before you put the spring in, lift the control arm back up into place and stick a bolt in to hold it there for the moment. Then position the jack under the control arm so when it is jacked all the way up, it is contacting the control arm on a good spot. Then lower the jack, leaving it where it is. Lower the control arm back down, put the spring in, and jack it up into place. The key to this is to position the jack so it is holding the control arm in the correct spot when it's jacked up, so you aren't trying to push things around when the spring is partially compressed. You should be able to get one side of the control arm into it's slot, align the holes with a screw driver, and slide the bolt through. Then you can let the jack down, move it over under the hole that isn't lined up, jack it up to where it's lined up, and slip the bolt in.
Done!
I hope that's not too complicated, I tried to be pretty specific. I wish I would have taken pictures, but I was too tired and frustrated when I finally figured it out.
PM me if you have any questions.
Jeff