Please pour some boiling water on the door for a few times. And it will be easy to remove.
The film should be removed within three days after you buy it! ! If there's any remains, you can scrub it off using some detergent! !
I suppose you can't remove the film because you didn't remove it immediately when you bought the door. You can find whether there is a part where the film curls. Apply some essential balm (or other oil) to the part and peel the part off at the same time. Repeating it for several times, you will find it's getting easier to peel. All you need is patience!
