It's a great spot to get to, great spot. Have a really strong light handy and don't be ashamed for swearing at Land Rover.

 

I believe the D2 and D1 are the same. Here is a video (which happens to be a D2).

From the comments section of the video...."This video applies to the Discovery I as well. The only difference is the D1 only has two 7mm bolts... one holds the sensor, the other bolts holds the protective cover and the other side of the sensor."

Notice he dropped the exhaust from the manifold to make room.