I've had to pull a couple of these, here's how I did it.
First, try to spray it a couple times a day, a couple days or so, with the penetrant of your choice (this REALLY helps!)
Remove the nut, and remove the adjuster bolt at about 1200 on the switch - it's about two and a half inches due UP.
With both of these out, use a couple pieces of flat metal stock (about 1/8" thick and an inch wide) to work behind both sides of the sensor and wiggle it loose. The flat stock has enough give to keep you from cracking the case easily, and still allow you enough leverage to get some motion happening. Remember that the nut screws onto a "collet" sort of arrangement, so you'll have to exercise some care (since it's aluminum, which isn't as "springy" as steel.) Slow and easy does the job. Once it's a little loose, it should pull free one-handed, and fairly easily.
When you reinstall, apply a liberal lining of some sort of never-seez inside the "fingers" of the NSS, so you won't have all this trouble when you pull it again!
5-90
