I want my rear windows to go all the way down instead of half way child safety setting. Is this possible?

First, we don't know what you drive...

https://www.askmehelpdesk.com/cars-trucks/when-asking-about-your-vehicle-303903.html

... and depending on what you drive, fully lowering the windows may not be physically possible.

First, we don't know what you drive.....

https://www.askmehelpdesk.com/cars-trucks/when-asking-about-your-vehicle-303903.html

...and depending on what you drive, fully lowering the windows may not be physically possible.

Yokon power windows 2009

Is the wheel well in the way?

Is the wheel well in the way?

I know nothing about it. If you think I can do it ,I can look at it. Perhaps I can bring it to the dealer.

Yokon power windows 2009

By design, it isn't mechanically possible for the window to go any lower.
There is no other window regulator to fit that application either.