Arm Replacement for U-Turn Tables?

Hello, I have a U-Turn table along with 8 other working, others not working as well, tables. I would like to switch arms (RB-300?) which I already own. Can this be done without too much of a mess with the plinth? Overall(with a couple of gripes) not too bad a deck but would like to upgrade the arm. Any experience or ideas would be appreciated. I also have a Grace arm from a recently deceased Connoisseur table arm model # escapes me at the moment.