FWIW, if you send the blower back to Vortech/Paxton the polishing usually runs $900, granted they disassemble the entire unit and rebuild it with new bearings so it is 100% fresh when you get it back, hardly worth the cost for being shiny if you ask me. If you polish it yourself you need to be very careful not to get anything in the blower or damage any of the seals. The compressor cover comes off and will be the easiest part to polish. The transmission is what is going to give you the most trouble and be more time consuming than anything else