Between the window winder handle and the door card is a plastic ring and behind the door card, against the door, there should be a spring which pushes the door card and plastic ring out against the handle.
To remove the handle you must push the plastic ring and door card back against the door as much as you can. This will reveal the pin which holds the handle on. There are holes in the handle at 90 degrees from each other to facilitate fitting in different positions so check which hole the pin is through and push it out with a small screw driver, drill bit or welding rod, as I do. It isn’t tapered so should come out either way and the handle will then be free.