Thanks for the reply Dave - I've searched through you tube and there is nothing that I can find about the E70 - there are a couple of vids with people doing similar on an E53 - and I'm trying to use that as an initial guide, but the mechanisms are quite different! The pelican parts site looks great but again they only seem to have DIY guides for the E53! I'll have a good look and see if any other models have a similar set up to mine.
Thanks very much,
Jim