Quickly modifying only MB2HAL?

Could someone point me in the right direction to quickly change MB2HAL?
I need to change:
github: linuxcnc/src/hal/user_comps/mb2hal/mb2hal.h
so the functions can handle more than 100 I/O points, which is the current limit hardcoded in the header.
[Which is incidentally a pretty small limit for discrete i/o!]

Is there a way I can rebuild just mb2hal and not mess with figuring out the entire linuxcnc build process? I'd prefer to keep working on the I/O and not get sidetracked enormously...

Thank you!

linuxcnc.org/docs/2.8/html/hal/comp.html