go to http://www.bmwe34.net/e34main/mainte...ical/sword.htm
Look in the middle of the page, I am six foot two and I was able to do this with a Phillips screwdriver and a bit of contortionism. The resistor is not always easy to pull out, you have to squeeze the clips on the sides and pull out, then plug the new resister into the harness and replace in the opening.
Cheers,