Hi Frank,
It is possible to remove the Diamond Shield Film, but you'll find it a painstaking, difficult process to remove it without damaging the paint.
There are a dozen YouTube Videos on the process and a number of websites selling special "juice" to help remove the stuff. And many businesses as set up to do this for you, as well. Most important is the use of special PLASTIC scrapers and great care.
Here's a big thread at IRV2.com that describes how one guy did this;
https://www.irv2.com/forums/f101/how...ly-175876.html
And here's one of many YouTube Videos: