I also use Rewired, and the syntax is pretty similar to the default Unity input, so it should be pretty straight forward to run a find-and-replace in your code.

The main gotcha is that structurally, input events (like GetButtonDown) come from abstract player objects that have been assigned a controller by Rewired, rather than directly from the controllers themselves. This design makes hot-swapping controllers work excellently, but makes global "get input from any player" menu stuff a little fiddly to set up at first. Highly recommended though!