Parking Brake Shoe Replacement

It's the 'drum in hat' style rear parking brake. The shoes and hardware can be replaced with the hub in place. It is a tight fit. There is a trick to slip the 'assembled' upper shoe strut and return spring past the hub and backing plate anchor.
It can be done easily with some practice. Do one side at a time so you have an assembled reference to go by.

The actuating 'finger' that hooks to the parking brake cable where the finger pivots on the strut is probably rusted frozen.
This finger passes through the backing plate and has a little rubber boot to keep dirt and water out. The new p/brake shoes are probably fine.
Place the strut and finger assembly in a vise and use solvent and heat to free the mechanism. Once it cools, make sure that it has free movement. I use a heavy oil or grease to protect the pivot from freezing again and then reassemble the rear brakes.
The problem with the current 'partially-applied' rear actuator finger is that it is keeping the rear shoes out in the applied position. This is why the drum won't fit back over them, even with the adjuster backed in all the way.
I'm sorry that they probably have to come back apart. I have never been able to really free these up while still on the car.