carbon fiber, billet and titanium....lots of it....you will need money....lots of it....
actually would be cheaper to upgrade the motor if you intend to go the full-distance on a weight reduction program
aside from stripping the bike of any and all extraneous embellishments.......serious weight reductions will come from wheel replacement to carbon fiber or magnesium,
exhaust cannister replacement,
brake rotors,
clutch assembly,
flywheel,
and one-for-one replacement of steel bolts and hardware for titanium materials
could also switch to a carbon fiber gas tank and other sheet-metal/plastic replacements