Tear it off with your hands if you can.

Wet it with a damp towel and then peel it off.

Use a hair dryer to hot air to heat the sticker on the refrigerator door, and then peel it off. Don't heat the sticker with a hair dryer for too long, and don't keep it too far away from the sticker.

If the sticker is torn off and leaves residual glue, you can apply wind oil essence on the residual glue, and then use a paper towel (or other things that can be wiped, but it is best to choose a cheaper one) back and forth. Just wipe it off.