I have been asked the question, How do you remove a stuck filter from your lens?
Stuck filters can be a major problem you don't want to break the filter or worse the lens. So here are a few ideas I have come across to help.
A rubber mouse pad, push the lens into the rubber side of pad and twist filter while applying pressure.
Place a rubber band around filter grasp band an twist.
You can also put the lens in the fridge for a short while the take it out it as it warms up it might expand enough to loosen filter.
A similar idea is to warm filter with a hair dryer but don't have it too hot and twist while warming.
Try wearing washing up gloves when twisting filter they give extra grip.
DO NOT USE WD40 OR ANY KIND OF LUBRICANT.
Do not squeeze filter ring whilst twisting as this can distort the ring and make it even harder to get off.
If all else fails you can buy filter wrenches from good camera shops, but the reviews on these items are mixed and the sizes available are limited to certain lenses and they cost you money. Camera Filter Wrench
I hope these suggestions help and remember when you fit a filter to your lens don't over tighten!
Remember these are only suggestions and I take no responsibility if you damage your lens or filter.