If you created an account with MyAlbum using an email address you can change the password and e-mail address on your profile. Select your avatar on the top right and select Profile.
I forgot my password
In the login screen 'Login with MyAlbum' click on the link "I forgot my password'. Enter the e-mail adress you used to create an account with MyAlbum. You will receive an email allowing you to reset your password and restore access to your account.