I see how to change my username, but how do I change my email address?
Your user address is part of your SAS Profile. If you change it there it will automatically be reflected in the JMP User Community.
To change the address in your SAS Profile go to sas.com/profile and click the "Change email" button. The next time you log out and log back in to the JMP User Community you should see your new email address on your Community Profile.