I wouldn't say it's hard, but it requires a bit of effort. After pulling off the bulk of it, you can use a ball of it to remove the bits that are stuck on, similar to the technique used to remove tape residue with a bit of tape. I mass loaded my T50RPs with Dynamat Xtreme and was able to return them to stock. The corners of the baffle were the hardest parts to clean up, so a flat surface should be easier to deal with. A plastic surface has more texture and the Dynamat will stick to it more. A smooth metal surface should be easier to clean up. Edit: I live in a warmer climate, so maybe that's why it was goopier for me to deal with than it seems to be for u guys.