Hi, Mican,
You should have received two text messages from MyO2 - one with your username and one with your password for you to sign into MYO2. You can do this by downloading the MYO2 app that you can get from your app store. Or, you can go to www.o2.co.uk and select MYO2 on the top right hand side of the page and sign in with your username and password.
If you don't have your username and password you can ring o2 customer services on 0800 587 4005 and ask them to tell you what your username is and to send you a new password. Hope this helps.
