I have a powerebook G4 15" that won't charge because the casing around where the charger plugs in has warped. If I piush the plug in and hold it I can get a charge, but as soon as I let go contact is lost. Apple store said it would be $600 to replace or I could try hammering in the edges around the charging port. I was thinkinh about buying a used bottom case from ebay and replacing it. How difficult would it be to switch out the bottom casing and is it a feasible solution?