You might get a couple different answers, but I'd take a little off the limb edges. When I build a bow and it comes in a bit heavy, I just sand all limb edges evenly until it gets down to weight. Now you don't want to go too narrow. Another way to reduce weight is to trap the back or belly.
I know some guys will sand the glass, but that makes me nervous. I don't want to cut into the fibers that are running the lenght of the limbs.