You can change your account details via "Account Settings".
Once logged in, hover over your profile photo on the top right-hand corner of the page, and select "Account Settings" from the dropdown menu.
Once on the "My Information" page, you can edit your account email address, password and your public issuu profile, among other account details.
When you initiate the email address change, a confirmation email will be sent to the new email address you are trying to add. Please note that it is important for you to be logged into your issuu account at the time when you receive the confirmation email and click on the confirmation link - only then will the email change go into effect.
Changing your Username
Unfortunately, you cannot change your account Username. Please see How do I change my account username or web address/URL? for more details on this topic.
Forgot your password?
If you forgot your account password, please see I forgot my password/need to reset account info for more information.