Ian, It's no problem to remove either frame rail one at a time. The most important thing is to have enough support under the engine and transmission to support the tractor and to keep it from twisting. I did my WC this way and had no problems at all. May I suggest a good quanity of cribbing, 4x4's about 3 ft or so long are what I used and then made up the difference with 2x4's and wooden wedges. It is also hard to get the rail to come off the front pedistal. I had to drive oak wedges in the crack to get mine to come apart. FYI the beams are not the lightest, its nice to have a second set of hands when it's ready to come off. There are some pictures here of mine.