How to remove the marvel chara-cover from the iPhone?

I just recently bought the iron man chara-cover and its supposed to slide on and off by the head of iron man. But now it won't come off and apparently that's an issue with these. I've pulled like crazy and it won't budge at all. Does anyone have any suggestions without breaking or damaging the case?

Push down on the chest part of the Ironman case to release the head from the body. It will separate.