Wiring for Hori RAP 4 - want to install Brook UFB

Hey guys and gals, I had a quick question for you. I want to install a Brook UFB in my Hori RAP 4 (5??) KOF Edition stick but I’m not sure how I can hook up the Home, share, L3/R3, etc buttons. Those buttons are not 24mm and are propietary buttons on the side of the stick. Are there wires in the current config that lead to those buttons that I can just plug into the UFB? I tried searching for a wiring diagram for this stick, but can’t find one online. Any help with that would also be appreciated. I posted in the Brook UFB thread but I’m not getting any hits. Any help is appreciated. Remember it’s the RAP that comes with the KOF 14 art on it . Thanks.

Not familiar with that particular PCB but Hori labels their PCBS well. So, open it up and check.
If not just prod a ground to the points to see if the buttons activate and label.