How do I change the primary email address associated with my account?

You can update the email address associated with your account by logging in on the web (i.e. not via the app on your phone).

Go to "Your Spaces" and click the gear wheel in the upper left-hand corner. Click "Edit Profile". Click "Add an email address..." and add the correct one. You can delete the incorrect or unwanted email address from your account after adding and verifying the new one. Just click on the unwanted one and then select "Remove".

You can also just change it so that the new email address will be your primary, but keep both emails on file as associated with your account (which can be handy for other people trying to find or invite you to their spaces). Just select the preferred email address and click "Make Primary".