pull the blower off, scrape the carbon off, and use a solvent/brake cleaner/gas soaked rag to wipe out the assembly and use a brake cleaner can with a straw to flush out the sides of the shaft while working it open/closed. with the blower set/propped on a bench with the tb side down and the pulley straight up youll keep all the crap flowing out towards the TB flange and onto the bench. hang it from a ladder over a bucket/garbage can even. (make sure to remove your evap solenoid on gen5's (do this before removing blower/etc as the evap hose snout is easily broken off, exceedingly common and quite annoying as your not likely to find an intact one in the junkyard.))
then just wipe out the inlet side and i toss a few drops of sc oil on the shaft to help lubricate and displace any future carbon buildup (plus you always have a couple drops in the bottom of those damn gm oil bottles, might as well use it)
