1: Make sure that you have already activated your license at https://sites.google.com/berkeley.edu/microsoft-365-activation/home
2. Launch the MS365 application you are using, such as Word, Excel etc
3. If you see "Activate Microsoft 365", click "Already bought office? Sign in".
4: When you see the MicroSoft Sign in, log in using your berkeley email account
5: You should see calnet prompt login screen. Sign in with your usual credentials.