Like Dwight said, it is usually rare where it actually has to be done. But out of curiosity, what size upper pulley are you using and how many miles on the car?
Definitely change the blower oil as part of your motor maintenance. The factory recommends changing the oil at 100,000 miles, but it should be done more often with smaller upper pullies. Here a link to my site for more information as well as instructions on how to change the oil. Changing Blower Oil
Like Dwight said, it is usually rare where it actually has to be done. But out of curiosity, what size upper pulley are you using and how many miles on the car?
I was thinking more along the lines of the kb and whipple. If there spun hard do they need a rebuild say around 10,000 miles or so? Or will they last 30,000