weight bolts are under the rubber bumper which generally pulls or screws out.
most weight bolts either have a hex or flat head and simple be screwed out. some are glued in place which require some heat, using a sodering iron, to break the bond before removing.
the general rule of thumb, for every 1 oz removed from the back will move the balance point forward 1" and the same goes for the oposite. for every 1 ounce added to the back, will move the balance point towards the rear 1".
of corse the reverse is true as well dealing with adding and removing weight from te shaft/joint end....