To do this will take a bit of practice- the exercise is fairly easy the hard part is rhythmic independance of both hands-hear Vic use this technique on the album "a show of hands"

O.K. firstly slow down this example. Now you should be able to follow the explanation of what is going on.

Thump the open strings with your righthand thumb, hammer-on with lefthand ring or 3rd finger whilst simultaneously positioning your 1st and 2nd fingers, then pop with your righthand Index or 1st finger, and then the higher note with your middle or 2nd. this may sound complicated but the thump and pops are just one wrist rolling action. Go on give it a go! n.b. Victor plays this faster and sings it at the same time.