Sandman I just posted a How-To on an engine mount, which contains a section on removing the starter. You will need to at least partially remove the starter to replace your crank sensor. Technically its not necessary to remove it entirely, but to me its easier, and you dont have the starter hanging from wires while youre trying to work in the area.
A set of ramps will make your life much easier in replacing that sensor.
I outlined removed the starter in this post, down toward the bottom.
http://www.automotiveforums.com/vbul....php?t=1076561
Its actually pretty straightforward.