Hi driddle,
Welcome to the Heartland Owners Forum and Family. We have a great bunch of people here with lots of information and all willing to share their knowledge if needed.
You should be able to just insert the pin back in to separate the contacts. I'm sure some others may have an idea also. If your not using the unit and you don't need the brakes applied, you might disconnect the battery as a lot of juice is being used by the magnets in the brake system and you might burn something up.
Enjoy the forum.
Jim M