New SIM card, but old phone # still shows

Hey,

So I have an iPhone 5S. I just changed my SIM card and got a new phone number. But my old phone number is still showing under my iMessage account and it won't let me just change it. How can I get this changed? You can see in the image I posted with this, the '920' was my old phone number. So my new number doesn't even show up at all, even with the SIM card in place.

Thanks,

Eric