You can deactivate your profile doing this:
- Click ‘Settings’ in the topbar (under your name/username)
- Under Account settings (scroll down a bit) you'll find a red “Deactivate profile” button
- Click the ‘Deactivate' button to deactivate your profile.
If you ever need the profile again, just log in and it will reactive automatically.
When you deactivate your profile, any active Premium membership will also be deactivated, so it won't continue in the future.