there are actually eight pieces. four legs, two ramps, and two cross supports.
the two ramps and the two cross supports form a rigid structure. they slide up and down through the legs. BP sells a kit that allows you to mount wheels under the cross supports:
http://www.bendpak.com/car-lifts/accessories/caster-kit.aspx
this allows you to move the lift around as a unit, but it is still pretty bulky.
were i going to move mine, i would likely lift the ramps up, back a long trailer under it, and lower the ramps onto some 6X6's onto the trailer, and lift the feet up off the floor. and drive it to the new location.
if you need to remove the legs for some reason, i would try to leave the "deck" alone. move the drive/hydraulic mechanism off the leg, and set it on the ramp. you could, if you can figure it out, lift the deck straight off the top if you have the room, and the mechanism to lift it (fork lifts or jacks and cribbing). move the legs and deck to the new location, lift the deck up high enough to stand the legs under it, and lower it down onto it.
i would be really reluctant to take all the hydraulics and cables apart.
i agree with the others, moving it in one piece seems like the easiest path, but not an easy path, if you get the difference.