Manually inflating rear airbag on a 1995 Gulfstream Sunsport

I can't get the electronic controls up front to work, so I'm trying to figure out if there is a manual way to get the fill valves to open on the airbags so I can raise up the rear for towing.  I've located the box that contains what is most likely a solenoid for each back and it has a lever sticking out of it.  However, I can't budge the lever by hand.  Does anyone have any documentation on how you can do this process manually, if at all?