Replace starter brushes

Has anyone ever just replaced the brushes in their 12RX starter from skytec?  or the rotax starter?  My $15 brushes are worn down and would be a simple fix to replace but skytec and rotax do not want to sell brush kits.   It is going on an experimental.   I have a spare skytec starter i took off in 2010.  It just needs new brushes.  The current starter 12rx in the plane now is also bad. I expect it to be brushes so I wanted to repair the spare i have and try it.  when i pull the current one, i bet it needs brushes also.

jh