Select the button with your name in the top right of the screen and then select Profile.
At the bottom of the profile page, select the Two-factor authentication… link.
If your app supports QR Codes, scan the QR code with your authenticator app of your choice. Alternatively, if your app does not support scanning QR Codes:
Select the Copy secret button to copy the secret to your clipboard
Enter the secret in your clipboard into your app manually.
Enter the code it returns in the two-factor code box.
Select the Enable two-factor authentication button.
Navigate to the Profile page and select the Two-factor authentication… link at the bottom of the page.
Select the Remove two-factor authentication button.