Signed in, go to Settings.
Change your email
Enter the new address. We send a confirmation link to it, and the change takes effect once you open it.
Change your password
Enter a new password of at least 8 characters.
Add two-step verification
Turn on multi-factor authentication to ask for a code from an authenticator app each time you sign in. Scan the QR code with the app, then enter the code it shows to finish.
You can also update your name and photo on the same page.