Jerry - As many will advise, you will need spring spreaders. These spreaders will take the tension off the shackles so they can be disconnected. Then after removing or lowering the axles, you can relieve the spring pressure so they can safely be worked on.
You might also take some time and think about anything that needs repaired or adjusted on the axles and their associated parts. Since you are going to have them loose anyway.
There is much printed information out there, and you can do a search on Fordbarn using "spring spreaders". There was just recently a thread discussing making your own rear spring spreader.