The grips, as you probably know, are an integral part of the frame. You can add decals, sleeves and such, but these are mostly for added "traction" in your hand and can only make a large grip even larger. If you want the grip smaller or the angle changed, this can only be done by a grip reduction. Finger grooves, if they are in the wrong place for your fingers, can be ground off and the frontstrap restippled.