I see this is an older thread, but I'll give a couple of suggestions as I had just changed my CPS.
Here is where I purchased my CPS from. Not cheap, but not $160.00 either.
http://catalog.worldpac.com/tayco/quote.jsp?clientid=alloemautoparts.com&cookieid=28F0MRM8B28F0MRQH2&baseurl=http://www.alloemautoparts.com/&partner=tayco&year=1987&product=F6010-12107&application=000006816
Go ahead and remove the oil filter. You don't have to change the oil to do that. It gives you that added little bit of vision that you need to do the job. Also, make sure your hood is ALL the way up to the vertical position. This will give you better access. The CPS is changed from the top, I do not see any way to do it from the bottom. It is a 5mm (if my short term memory serves me) I used an allen bit in a socket and a 3 inch extension. It was mildly difficult for me, but I wrench for a living, albeit on airplanes.
After you have it out, clean up the area using a solvent (brake cleaner or the likes) There is no adjustment on the sensor. It just sends a signal from the poles on the flywheel to the 'computer' to let it know the engine is turning. I believe that my original sensor (195K) went to an open ohm reading when it got hot. It would start after a while. Put the new sensor in and make sure it is tightened flush.
Just my limited experience on this.
Sam