1. Get the account you want recoveries removed from locked.
2. Click I do not recognize these questions.
3. continue with unlocking.
4. wait for recovery email + recoveries are removed.
Simply use the my password was stolen recovery option and if your appeal is succesful your recovery questions will be removed. With the lost password option they stay.
just register an email, recover a stolen password. then you should get an email, go through the process and your recoveries should be deleted. it worked for me anyway.