Place your first, or index finger on the 3rd fret of the 6th, or low E string.
Using the center of your index finger, mute the A or 5th string so that it does not sound when plucked. The open A or the B note that would be formed is not part of the G2 chord, so make sure there are no overtones when you hit the A string.
Put your third, or ring finger on the 2nd or B string on the 3rd fret. Keep your index finger in place without moving it as much as possible.
Allow the middle portion of your ring finger to hold down the high E or 1st string on the 3rd fret. At this point, you should be using your finger to play two individual notes clearly.
Place your second finger, or middle finger on the 2nd fret of the 3rd or G string.
Pluck the notes individually, starting with the 6th or low E string all the way to the first, high E string to make sure all intended notes are sounding clearly. Make sure the A string is still muted.