BMW Repair: crankshaft sensor location, crankshaft sensor, camshaft sensor

Question
I have a 1999 740i model with 120,000 miles.  My "check engine" light is constantly on.  The code book identifies problem as a crankshaft sensor unit.  I have bought another one but do not know the location for the replacement.  Also is it easily accessible ?  Thanks in advance for any help.

Answer
Don, cranksensor is toward the bottom of the transmission bellhousing. Are you sure it isn't Camshaft Sensor. I see them failing more often than Crankshaft sensors. Cam sensors are on front of cylinder head and have length of wire on them and a connector at the end. Make sure you replace the O-rings if you do the Cam sensors.
-Evan