E30 Zone

I have followed the instructions on the forum (mainly posted by Brian) to adjust the parking brake but failed at the first hurdle!
It seems when the brakes have been adjusted previously one of the nuts at the handbrake end (inside the car) has been wound on completely, both were at a similar point but I am only having trouble with one of them.
Basically when I try to loosen the nut it turns the cable and thread as well, tried getting some grips on it to hold the thread but this is only chewing the end of the thread up.

I did manage to adjust the shoes anyway so it seems OK but I will need to replace the shoes in the not too distant future.
Does anyone know of a procedure for unlocking the nut or should I cut the cable when I change the shoes and attempt to replace the whole cable?

Mole grips on the thread will have just worsened the situation, the back of the threaded section is square and locates into the handle, if its turned out of this then it just needs squeezing back together with grips

Thanks Dan, I can't see anything that looks like it can go back in, is there a diagram anywhere showing the fitting?

OK, had another look at the handbrake at the weekend and managed to loosen the nut as it was hard against the square locator. Problem is the square locator fits all the way through the handbrake and back.. Whatever it is meant to lock on is missing from the handle I think (one side is ok the other one will keep going in and out)

So can I adjust it in this state? If not what to I need to do to repair the handbrake?