I've seen several posts where owners have had bad oil level sensors, but I don't think anyone has posted their experience with changing it themselves.
To start, my oil light came on. I checked the oil level and it registered "OK". I never checked the dealer price to replace the oil level sensor, but the part price was $223. I opted to go with Autozone for $158. I down loaded the service manual and it had a nice picture of how the sensor is located inside the lower oil pan. The whole process of replacing this sensor was not hard.
1. Jack up car and remove bottom cover.
2. Drain oil. I let the car sit overnight to make sure that it was drained.
3. Remove the harness from the sensor. The service manual shows a picture, but I couldn't find it until I had removed the oil pan and saw where the sensor was located. The harness is located on the passenger side just above the oil pan. I used a small pair of pliers to remove the harness.
4. Remove the bolts from the two coolant lines connected to the oil pan, then remove all of the oil pan bolts. These are star headed bolts and you will need a #10 star socket.
5. Remove the oil pan. This was the hardest part for me. The pan is held together with a sealant. There are two flanges located on the drivers side where the pan can be pried loose.
6. Once the pan was off, I used a plastic scraper to remove the old sealant. I sprayed the pan with brake cleaner to clean and it also helped in removing the old sealant. Spraying a rag with the cleaner also worked on cleaning the upper pan.
7. The sensor is two parts connected by hose. There are two bolts for each part. These bolts were also a star bolt needing the same size socket as the pan.
8. After removing these two bolts the part that connects to the harness had to be pried out with a screwdriver as it has an o ring.
9. When replacing the new sensor, rub a little oil on the o ring. I went ahead and replaced the harness at this point. Be carefull of how the harness is inserted. There are three pins inside the sensor that the harness must be aligned with.
10. For the sealant on the oil pan, I used Permatex black gasket maker and followed the instructions on the package. I laid out a little over a 1/8" bead all aroung the pan. Once I had the pan back in place, I just snugged the bolts until the sealant started to squeeze out and let dry for an hour. After an hour, I tighted about another half turn. I let this dry overnight and then tightened to 10 ft. lbs.
11. Replaced oil and no more light.

As I said, not a really hard job and I saved a few bucks. Best part is I didn't have to leave the car with the dealer.