how do i drop the gas tank in a 64 galaxie and what should i charge to do it??

Dropping the tank is simple. Undo the bolts at the rear of the tank, and the tank will drop right out. IF the bolts come out right, it takes about 15 minutes. If the bolts are stuck, you will need to soak them in penetrating oil. The bolts are simple carriage bolts, so easy to replace with stainless when the time comes to reinstall. If the straps are bad, new ones are probably about $35, and clip into brackets at the front of the tank.