Precise timing is required for this trick as doing wrong will cause you to fail faster than not strumming at all. Play the notes as if it was a double note instead of a triple note. You must strum up and down at a constant rate in order to do this successfully. You must play the solo as usual, but afterwards the rest is easy. You should get at least a 90% on the song if you get 60% on the solo and do well afterwards.