Thanks alot for the pointers guys. I'm realising 2 things :
1. The Bentley manual is a pile of rubbish. Spent €100 on the damn thing and it hasn't helped me once. The procedure in the manual basically says 1-2-3, undo the bolts, drop the cover, whip out the old filter and shove in the new one and bob's your uncle. Says nothing about how difficult it is to get the cover off, nothing about the special clips used on the filter hoses nor does it say a dicky bird about having to remove the handbrake cable.
2. BMW's were never built to be easy !
It'll be a while before I've a chance to attack this job again, perhaps the weekend after next. I'll be sure to update you on how it goes.
Thanks again, some very helpful pointers here.