almost got the rear subframe removed but can't see a way to get the Parking Brake cable out of the backing plate (1995 legacy, rear drums).

heat + vicegrips= victory

There might be 3 or 4 tabs on the inside of the backing plate that have to be pressed in before the cable can be pulled out. I've seen them like that, and some have a spring clamp that slides into two grooves on either side of the cable.

Could just leave it and disconnect the cables under the parking brake lever.