I cant understand how it's single notes but he's got the strumming action in place and keeps the rest of the strings constantly muted. (That's what i assume is happening there..).
Hate to be the bearer of bad news, but that's just practice. Good strummers have their hands constantly in motion - that's how they keep the beat - and also have very good control of hitting the strings they want to hit. It's not really about muting at all. It's about accuracy. The only way that's going to come it to do it. And a great way to get started is to get used to playing partial chords or chords that require you to just hit certain strings.
It may indeed seem very difficult and an impossible goal at this stage of your playing, but it will come. We've all gone through it. Some still are! :wink:
Peace
