How do you take the wrinkles out of plastic that has a picture on it?

I have an Elvis Picture on a piece of plastic that is a wall hanging. They call them add ons.How do you take the wrinkles out of plastic that has a picture on it?
Try a blow drier set on low ...apply heat to back side if possible. Thank-you....thank-you very much!How do you take the wrinkles out of plastic that has a picture on it?
I concur with M%26amp;T. Don't hold it on any spot for long either.
Put it outside in the sun. Then say,';Elvis has left the building';.