How to replace bearings on mainsheet traveler bearings

[bumsailor]

Hello, does anyone know how to replace the bearings in the Amiot car on a 2003 SO 37?
It has allen head bolts on each end.  I'm not sure if you need to remove the car to do this (similar to Harken) or
just (if they are not frozen) remove the bolt(s) and push the ball bearings in.

I have another post on removing the entire assembly, but I would prefer just to replace the bearings if possible.

Thanks!!