If your plate is made of metal or ceramic, you can try running it under hot water for a few minutes to loosen the adhesive that is holding the two pieces together. You can also try using a heat gun on low setting or a hair dryer set to high. Hold the heat source about six inches away from the area you are trying to straighten and move it back and forth until the adhesive begins to soften. Once the adhesive has softened, you should be able to slowly straighten out your plate. If your plate is made of plastic, you will need to use a hair dryer set on high or a heat gun on low. Slowly move the heat source over the area you are trying to straighten until the plastic becomes pliable. Once the plastic is pliable, you should be able to slowly straighten out your plate