How to take otterbox off of the iPhone 5?

I bought an iPhone 5 a few weeks ago, at the store where I bought it I purchased an outter box for it, it was installed that day by one of the workers. So now instead of this bulky case I want to change it for a new case I bought today, but I don't know how to take it off. Can someone help me? IMessage/email me if you want, cuz I don't know how to reply on here.phunk_rocker_jerk27@hotmail.com

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