How to overtone sing

1. Is overtone singing hard?
2. Can anyone overtone sing?

Is overtone singing hard?

If you listen carefully, you'll hear a overtone scale from low to high. Of course, it's hard to do it with control and volume though. P.S. It helps if you know how to whistle and know how to control a whistle note with your tongue. It's really not that hard to do.

Can anyone overtone sing?

Yes, anyone who can speak can learn overtone singing.