@Anonymous User
Welcome to the forum. You should still be able to sign in to watch using your current login details, check on your My Account > Account Details page to see what your username is.
However if you need to change the email address on your account you can do this by going onto live chat and requesting an update. You can get to live chat from the Contact Us page
https://help.nowtv.com/get-in-touch
(expand the Anything Else section at the bottom for options)
