Patch panel question

OK--So I found some parts to pick up for my 68 Valiant on the way down to Indy on Thursday,The 68 has a big crease in one rear quarter hence the patch panel,I have never cut body work-How do you remove a rear quarter panel???? or do i cut a lot larger than i need--Ok and if I can cut it a lot larger can I use a sawszall -No power out in the field where the car is at--Steve