Open the Blitz App. (This also works on the web version of Blitz.)
- Widen the sidebar if you hadn't already by clicking the button in the top left corner.
Click the cogwheel at the bottom of the sidebar to open up Settings.
In the "My Account" section, click the "Edit" button next to your email address.
Enter the email you'd like to switch to and click "Send."
Confirm the change via verification emails sent to both accounts.