Re: how to release brakes when backing up.
Yes, there is a fairly simple way to activate the trailer brake lockout soleniod so that you can back up the trailer. This is procedure FOR EMERGENCY PURPOSES ONLY!!!
On the trailer 5 pin flat electrical connector, the blue wire is for the brake lockout solenoid. This should be the blue male pin on the end of the connector. Plug this blue pin into the female pin for the brown wire on the 4 pin flat electrical connector on the tow vehicle. Connected in this manner, forms somewhat of a "T" shape and results in only 1 electrical pin being used on each half of the connectors. Then turn on the lights of the tow vehicle. The brown wire is for the marker/tail lights on the trailer. By turning on the tow vehicle lights, you apply power to the brown wire (of the tow vehicle) which is connect to the blue wire (brake lockout solenoid) on the trailer and energize the trailer brake lockout solenoid. Ground for the circuit is provided through the hitch ball, and the end result is the trailer can then be backed up.
Again, this is only to be used during a temporary emergency situation.