The upper intake manifold needs to come off to get to the plug. Kind of a pain, but it's not too hard. You'll want to buy two new gaskets for where the upper and lower intakes meet. Part #11611247478
http://www.realoem.com/bmw/showparts...69&hg=11&fg=40 Someone brought up the idea of cutting and splicing the new sensor end onto the old plug end. Might work in a pinch if done properly, but I'd take the upper intake manifold off.
Here's what it looks like with the upper intake manifold off. You do need to remove some simple ancillary things to get to this point like the throttle cable, main intake boot, a couple simple electrical plugs on the throttle body and a few vacuum lines.
