What about the lid that covers the other lid?
After the two cap on the refrigerator a few minutes, remove the buckle in the bucket, with 60 to 70 degree water slowly poured out in the lid, pay attention not to let the hot water poured into the inside of the lid, poured out immediately after ten seconds, a cloth pad, unscrew. Most cases can be solved.
I don't know what kind of material and shape you're talking about. It'll only give you an easy way to do something that usually works
Note that if it is a plastic lid, the temperature of the hot water can not be too high to prevent the lid from deforming.
