Stephen Kraus

First time posting (long time lurker :P), I recently purchased a Kowa 16H on eBay, and when it shipped I realized it came with a 52mm filter attached (possibly hot glued?) onto the rear of the lens (not disclosed on the eBay description). I was happy at first, as this allowed me to mount the lens to any taking lenses with a 52mm front threat without using a Redstan Clamp, but it's proving to be really hard to focus without screwing up alignment. So, what I'm wondering what the best way to remove it would be, without potentially damaging the optics near the rear of the lens. Thanks in advance!