I got it open. Thanks!

I sprayed it down with penetrating lubricant. Then ran a heater directly onto the area.

There is a big chunk of ice around the hook that's attached to the lower frame. Maybe the latch was stuck on in it.

I really had to hack away to get access but what's done is done.

 

If you look down into the gears there is ice blocking the movement. Annoying.

Maybe none of that mattered, because the cable was also stretched and not release the latch.