What's he having problems with, exactly?
The best advice I got was to expect to take several months to be able to get a decent sound out of the flute.
Three months, I was told. Then, after that, you can kind of start playing something. It was close to that.
A whole lot of things have to come together to make sound happen. Far more things than with a whistle. You'll get one thing to work and a partial sound will result, then maybe you'll get another and better sound, then everything falls apart.
But, bit by bit, as you work at it over time, more and more things come together. If you can play a whistle, or have some clue about music in general, then I think things will eventually happen for you.
You have to begin, I think, with just trying to get sound out of the headjoint. Plan to spend a number of days to a week doing that. When it's instinctive and you can do it every time you bring the flute to your lips, then move on to trying to cover the holes and get a sound, too.
Especially if you are alone, you have to find the sound and how to make it by trial and error. The tutorials are good, but you will have to follow them and still go by trial and error.
I second the M&E website,
www.irishflutes.net. The Cronnolly's have good instructions there for getting started. I found it most useful. Very down to earth and understandable.
http://www.irishflutes.net./mef/Tutor.htm