I'd start off by taking all the plates out and cleaning up the whole assembly.
While you're at it you will be able to see if the drum or basket is badly notched or if any of the tangs on the plates have got too badly distorted.
It will probably take less time to strip the clutch plates out than it does to get the fairing off!
7th year in DD #68 and getting slower by the year
Shiny '92 851 Strada, 620SSie DD racer