I got my crankshaft sensor replaced (as I was talking about in the other thread) but the camshaft sensor has problems too. I thought I'd try to do this one myself. Following the instructions in my haynes book, I took off the sensor, took off the drive belt and rotated the crankshaft pulley to a position where the sensor magnet was visible in the sensor hole.

The magnet had been damaged and was the reason I was having problems. I try to pull out what was left of the old magnet casing and wasnt able to get it out (its a pain to mess with). Unfortunately I think it has to be removed and installed from inside the engine.

Am I correct? If so what all is involved in replacing the sensor magnet? Does the engine have to be lifted out? Is it accessible if I drop the oil pan? (if so I might do it myself) Any ideas on the cost to get it replaced? I already have a magnet. They only cost $9.

I've come across this problem many times changing ABS wheel sensors on Fords at work. The metal casing of the sensor often seizes in the housing.
The best way I've come up with to extract them is to use a small flathead screw driver or a nail (something with a small, narrow head) and try to wedge it between the metal cap on the sensor and the housing with a hammer. if you manage to get your tool wedged in there, simply pry inwards so there's enough metal to get a pair of pliars on and just pull it out. Penetrating fluid usually helps in this situation as well.

Let me know how that works out for you.

I think you are thinking of a different type of casing. The one that I have is in plastic. Somehow it got damaged and the magnet broke out of the casing. Looking at the new magnet and my inability to pull the old one out from the sensor hole it must mount from the inside. All I am wondering is if the magnet can be installed via removing the oil pan, or if something more serious has to be removed to change out this magnet.