How do I change default email to another?

How do I change default email to another?

When I signed up, I set my default/admin email address as 'hello'. I wish to change that to 'chris'. I cannot find this setting.

When I login to send an email, 'hello' is the default... although I set 'chris' as my primary. 

I no longer wish to use 'hello' at all.

See here: http://d.pr/i/EjQv

Thank you!

~chris