Did the seat belt method earlier. Grabbed a couple of lengths from a scrappy.
You need to jack the car up to just before the point at which your springs become loose, mark the shock, take the shock out and cut the seat belt to length and double up (i only doubled up at the ends because I didn't have enough) and melt holes into the belt so when fitted the shock stays at the marks length:
I've lowered mine on e36 lowering springs chopped to fit. Just some that I had lying around. Will post some of that info up on my build thread. This method works a charm, cheers Imrdave!