First click on your profile image or initials in the top right corner to open the hamburger menu. Then click on Settings.
On the Settings popup, click on "Change email". Type in your new email twice, then click Update.
You will be sent a verification email to the new email address. Click "confirm email change" in order for this change to take place. Note: for security purposes, this link expires in 24 hours.
After confirming the change from the verification email, you will be automatically signed into Hound with your new email address. All Hound email notifications will also be sent to your new email address.
IMPORTANT NOTE FOR RALLY USERS: your email address will also be changed in Rally, so please remember to log in with your new email there too.