RPi2, Retropie 3.1.

Hey everyone, I’m building my own arcade machine and I would like to simply change the controller settings for Mupen64 to recognize my joysticks as the analog stick. I have properly setup a Xin-Mo/THT THT Arcade console 2p USB Player, and it recognizes the joysticks as a D-Pad for every working system, but I would like to switch it to the analog stick specifically for N64 games.

I have tried looking through the config files mentioned here: https://github.com/RetroPie/RetroPie-Setup/wiki/Nintendo-64%5B1%5D . I have also tried following some of the steps in this video: https://www.youtube.com/watch?v=lh0n5PWN2lI but I haven’t discovered the exact change that I need to make.
If anyone can help me with this I would greatly appreciate it!
Here is a picture of the controls: http://i.imgur.com/zOO294z.jpg