strip the drum out then use a hammer and a old extension bar to knock bearings out .
can pull them back in using a couple of pieces of 4 in long plate 1/8" to 3/16" thick holes drilled in middle to take a length of all thread
basically you put the thread through the drum fit the bearing fit the plate fit the nut repeat this operation on the other side run the nuts down finger tight ensure the bearing are sitting square now start tightening using 2 spanners keep checking that they are entering hole squarely.
if no fabricated tool can be made like the above its back to the hammer and a large socket method then refit all parts you removed to get to the drum assembly
wirecutterman, May 2010
