camshaft sensor replacement on 2002 GMC Yukon

I am attempting to replace a camshaft sensor for my mom and dad. I can't find consistent information on where it is located. Where is it and how can I get to it and how do I know I have the right part when I disconnect? Pictures would help a ton!! They have a 5.3 L engine.

Asked by for the 2002 GMC Yukon