Figured it out, and posting incase anyone else runs into it.
to reset the parking brake, fully unplug them. The clip is a little fidgety. If they don't pop off, then the clip is still engaged.
Then run 12V to each of the 2 pins. If it goes the wrong way, reverse the polarity.
I expected a more complicated mechanism but it's really just 2 wires per parking brake.
