If you try to remove it, you will very likely destroy it. You would be best off to just mask it off and paint the door that way.
You can have a new one made if needed, but be sure to take some very good photos of it first so that they can get the font and date exactly right. The original Mylar stickers have a lot of variations.
Better yet, do that and then order the new one before trying to remove the old one so you can compare them for accuracy.
Contact Dave at
www.ecsautomotive.com to inquire about a new one.