Best way i found to remap buttons was to add the game to steam as a "non-steam game", then enter big picture mode on steam, find the game, and then you can change the control scheme for that game. i just changed the left stick movement and right stick camera movement but you can change the buttons around however you want.
there's a video on how to do this by JudgeMagistR on youtube if you need it.
Hope this helps