Thanks, but it seemed to me that I might as well just send the whole lot at once. If I get the 'change address' wrong, then I lose the bitcoins. If I get this wrong, then I lose the bitcoins. May as well try to send them all at once, at which point they will be safe. And as that is simpler to do, I figure I am less likely to make a mistake this way.

But that is a nice well presented video. Thanks for posting it.