If you have a humbucker that’s epoxied it is more difficult to reverse the phasing. If you have single conductor shielded wire, you can sometimes do some fancy wiring by reversing the ground and hot leads. Using special magnetizers with custom probes or pole pieces enable you to remagnetize the magnet within the epoxied pickup and reversing the polarity. If you have two or four conductor hookup wire will allow you to do some custom wiring.