or find a local rebuilder and have them do it and TEST it under load.
Yes, it is easy to rebuild one.It is an interesting project for which there are many diy instructions-it is a generic Bosch starter motor. It is the load test that is tedious - usually on your car ! And if it is an unsuccessful rebuild ,you have to r&r and buy one !
Bosch Starter Rebuild Kits? - Pelican Parts Technical BBS
https://www.youtube.com/watch?v=mJM2veUNBc0
Bosch alternator rebuild kits Alternator Parts - Starter Parts - Repair kits
for less than $70, is it worth it?
http://www.ebay.com/itm/100-New-Premium-Quality-Starter-Porsche-Boxster-2000-2005-3-2L-3-2-V6-17758-/361103844275?hash=item54137763b3:g:77QAAOSw54xUWUi x&vxp=mtr