Do I remote the antenna in place and put this one in? Or do I place on top of present antenna. Can I have a very detailed description of where the antenna is placed and plugged. Thank you

 

Well, first off, what you are asking is very confusing.

The 2016 basic remote start antenna is located above the headliner near the center of the roof close to the mirror.

 

Is this the integrated factory remote start system? Are you sure the existing antenna isn't already for remote start?

My 2011 XLT did not come factory with remote start, I didn't order it that way. However, all I had to do was bolt in and connect the antenna module (I don't remember the part number or specific description) and connect a modular plug or two behind the glove box.
When my truck when in for warranty work a few weeks later, my dealer enabled remote start while IDS was connected and cut the two Ford keys for free.
I then joined the two new Ford keys with the remote start button myself.

I didn't have to run any wires so possibly this has changed with newer models.