You could try and lose some of the metal bits off the engine. Replace the front cover with carbon fibre. Maybe the same with the airbox and starter lid. Maybe there are lighter starters available. The indicators can be replaced with something lighter. It just starts to get a bit expensive and time consuming, after the obvious stuff. Take the tools out, they can go in the luggage. Fit lighter mirrors. I don't know if there is much of a difference in shock weights. Batteries are heavy as well, Handlebars, could be another one. I am sure some are lighter than others.