I recently purchased a blackberry curve 8530 from a friend. I went to set up my BBM and his information is still on there. How do I remove his information or sign him out? Or do I need to go to a Sprint store?

You can delete his contacts one by one right in BBM. Hopefully he has told his contacts that he has a new device and his old PIN is now somebody else's PIN.

You can do a security wipe of the device (Options > Security > Security Wipe) and remove all of the previous owner's personal information.