how to replace crankshaft sensor.

My 1997 quad 4cl car For months, has been dying periodically when running at 20-40mph, not setting any codes, it immediately restarts when I shift to N & crank. I replaced Idle air control valve myself & it seemed better, my gas miliage imporved greatly but dying not solved and much worse at high elevation when I took it out to Colorado. Finally when it died yesterday it set code P0335 Crankshaft Position Sensor Circuit.

Can a bad CPS cause car to die?
I can change oil, plugs, hoses, wire stereos, do other minor things, etc... is this something terribly diffcult to replace?
What's it look like & where is it? My Haynes Manual indicates the bottom of DIS (which I don;t know what that is) assembly but it often is misleading because it covers so many cars, engines.
Pep Boys says that the part is avail for like $30, so I'd like to try myself if poss & see if this fixes.

This is an older post, but in case you're still watching it (or someone else with a similar question views it), here is a link to the AC-Delco website picture of the part (#213-970)
http://198.208.187.182/internet/ViewPartImage.jsp?acdelcoPartNumber=213-970

It is located in the front/center of the engine block, near the starter.