It is located towards the top rear of the engine on the left side. You will need to remove the top engine cover in order to access and replace it:
remove the engine sight shield.
Fig. Using J 41712 or equivalent, remove the oil pressure sensor.
I've tried removing the cover and was unable to locate the sending unit. Is it really buried back there? Also, what is J 41712 or equivalent? Do I have to buy a special tool?
Have you actually changed one or is your answer just a cut and paste from a manual?
I have changed a few of them. It is a little buried, but is accessible without removing anything else.
The J 41712 is just a speciality socket made to fit over the entire oil sending unit without breaking the top connector. They are about $10 at Autozone or Napa. You can also use a wrench, but there isnt much room for much more that 1/4 turns of the wrench at a time and therefore somewhat time consuming.
here is another diagram:
If its not more than 15yrs old, it should still work.