Theoretically it's a simple movement of the existing gearboxes to make room for a second gearbox on each side. The towers themselves will stand up to the torsion the Mecanum wheels would produce (at least outside of competition), so a direct wheel swap would be fine. It looks like you would have to purchase (based upon what you've given us):
- 1 Mecanum wheel set
- 2 AM Toughbox
- 2 AM Toughbox chassis braces
- 2 CIM motors
For center of gravity on a competition field, you would want to put the wheels more inline with the chassis; yet for offseason prototyping this will not skew your results much.