You will be requested to input the domain name and email address you registered with and will shortly receive an email with a temporary password (valid for 24 hours).
After you log in with the temporary password, you will be prompted to create a new password immediately. In the Current password field, input your temporary password, and in the New password fields, enter a new password.
Once you are done and hit Save, a pop up will appear to let you know that you have successfully reset your password.
When you go back to the Admin section and signin again, your new password will be in effect.