I'm sure it's possible, but I would highly recommend only swapping robots if the controllers are the same. The I/O, settings, System Variables all are likely different between two different controller versions, and you're likely to run into a bunch of miscellaneous problems.
It's fun enough swapping robot mechanical units when the controllers are identical, it would probably turn into a 2+ week project if the controllers are different.
You'll need the CORE software to swap them around as well.