You'd need rewire the LT wiper to the RT line and vice-versa, so 2 trace cuts and 2 wires to solder in there is all that it really takes.
It could also be done with a DPDT switch so it could be swapped back and forth between the stock and swapped layouts, then you end up having 2 trace cuts, 6 wires and need someplace to mount the switch.
The only issue you may run into is that some controllers can be really picky about the Analog lines, so if you get one that doesn't work right after being swapped then it will need to be tweaked a little bit. It's pretty rare for it to happen, but every now and then does.
Specifically how you'd go about it depends on the controller version you're dealing with, as there are 6 of them right now, 2 wired and 4 wireless versions, but they all get done the same way in that you only need to swap the LT and RT lines with each other.