If it is the Air Force One, there is a tee in the vacuum line going to the master cylinder that will need to be removed and a connector put in to replace it. That line is cut and the tee is installed at the time of the AFO install. Then, I think you can just remove everything else without worry. Should be an air connector, electrical connector and break away switch on the front of the vehicle. The box under the hood and the air cylinder that pushes on the brake pedal arm. A wire attached to the vehicle brake switch. Some air hose and a little bit of wire should be all there is.
I would find out which brake system it was and as suggested before, contact SMI. I'm sure they will give you the info you need.
Pete - Full Timing
2000 Country Coach Magna 40', CAT C10, #5892
2006 Jeep Liberty