Last year I replaced my top seal with one I ordered from WCM.  Simply
remove the screws from the rack and lift it off.  Remove the remnants of
the old seal, clean up the edge and install the new seal with the
recommended 3M adhesive (I forgot which one).  BTW, while the luggage
rack is off, take the time to clean up your top underneath.  I cleaned
mine thoroughly and waxed it before replacing the rack.  Good luck.

Warren Lail
81 Westy