Edit firmware for Midi Fighter mod?

I'm considering modding my Midi Fighter classic, adding more analogue controls and buttons then the expansion ports allow. I have worked with multiplexers on a few occasions for various applications (none of which on any midi controllers) at Uni, so am confident I can implement them correctly. The thing that scares me off is editing the firmware so it works properly. To what extent would I need to edit the firmware and how easy is it to do so? I know a few people who can write code in various languages so would it just be worth giving it to them to try? Or is it basic enough to attempt myself (I have very limited coding experience)

Cheers.