just in case you decide to rebuild the transmission yourself, here is an excellent write up by one of the forum members.
the PDF file is too large to upload to the forum, so you will have to download it from my dropbox.
here is the link:
https://www.dropbox.com/s/n1qdzgr5hlkcfon/2002BoxsterSTransmissionRebuildDecember2011Revisio n3.pdf?dl=0