I have a cab on my L3600 - the predacessor to your model, and have naturally disassembled a few pieces of it. If you can get a hold of one, it probably wouldn't be too difficult to iinstall. the cab is fairly well self contained.
You'd probably have four connections to make.
1) Bolt on the Cab
2) Tie in the electrical system to a couple 30A circuits
3) Tie in the heat coil to the tractor coolant system
4) the most difficult would be the AC - install the compressor and the mini radiator then run and install the coolant hoses. You will have to have a shop pump down the system before the coolant gets released.