So I finally got around to doing this job.
It is possible to do without dismantling the complete rear brake assembly.
This is how i went about it.
Firstly , thoroughly soak all nuts, bolts and union's in penetrating oil, every day ,for at least 3 days before you start.
Dont bother to try and undo the upper brake pipe from the top union, just cut the flexy and then you can undo the top union by holding the brake pipe connector still and turning the flexy.This prevents the possibility of damage to the plastic coated brake pipe, and the bottom flexi pipe union can be removed in the same way.
Disconnect the electrical connection for the abs sensors on both sides and unclip.
The brake pipe feed into the rear cylinders will probably twist and shear even if you remove some of the plastic coating from around the joint, I did try and remove them in one piece but they sheared, so made a set of new ones from copper.
As for the eight studs that hold the brake drums and stub axle onto the axle, 4 of the nuts came off and 4 the complete studs and nut came out, so fitted 4 new nuts and thread locked the 4 studs back in.
Once you have disconnected the brake pipe feeds to the cylinders, and the 4 fixings to the back of each stub axle, nearly forgot to mention , disconnect both handbrake cables from the handbrake itself in the cab, so now you can remove both rear complete drum assemblys and just place them under the car.
Parts I bought to do the job,
2 rear brake flexi pipes
5 (in a bag) stub axle nuts
4(set of) flexi pipe securing clips
All ready had the brake pipe kit to make new rear pipes.
Hope this helps.
Cheers
Tony