Parking brake won't set, stuck in up/off position
 

On my '93 Sierra, the parking brake is hung in the up position. It won't release, so I can't set the brake. I've pushed and pulled on everything I can think of and can reach. I've pushed it really hard, and nothing seems to work. Online, they purport to show how to release it, but nothing works in this case. I could live without the parking brake, but I put my boat in on some really steep ramps...I don't want to end up in one of those photos where the truck is mite near underwater from the trans popping out while I'm between boat and truck.

Thanks seriously for your input!
Julabee Jones