Hey bro, try this... It works for me. Get those thick styrafoam. The kind u get in a box when you buy stuff. Place it on the ground, press ur lens (mounted on cam) on the foam. The filter will sink into the foam and will provide a good grip. Press firm downwards and twist ur cam. Filter will be loose. Try not to pry or use tools on the filter to prevent warping. This method is safe and effective.
I always remind myself not to screw the filter too tight. As long as it's screwed in, should be fine. Better to lose a filter than to lose a lens.
Gd luck bro... =)