Welcome to JustAnswer.com! My name is DriveFast71(Ron) and I will do my best to answer all of your questions completely and accurately.
(If this is a 2005 Lincoln Navigator, it was not offered with the 4.6L, only the 5.4L. I will base my answer on this. If you have the Aviator with the 4.6L, let me know...)
This vehicle has 2 camshaft position sensors. One for each bank. They are located on the front of the engine, just below the valve covers. Simply unplug the electrical connector, remove the mounting bolt, and pull out the sensor. Reverse to install.