if you have alreqady attempted a few times the same piece it will not stick. Esp if you did not properly clean 1st. 1st need to use rubbing alchohol to clean and prep surface. Gets off all oils and armoral. Then use a hairdryer to heat surface and the sticker. place and leave alone. Once its on it will not want to restick well
the more prep that has been used on the plastic, the more you are going to have to clean it. I had to sand a place on my guage pod to place my shift light. (I dont suggest that) It had 4 years of prep on it and it would not come off no matter what chemicals I used. It wont stick worth a flying poopie if it is cold either.