The only difference between accompaniment strum #2 and strum #1 above is this.
This strum starts out with a quarter note. At the moment, every time you see a quarter note, miss the strings right after it. So miss the string on the "& of beat 1. You will not see a circle around the rhythm on which you are going to play open strings. It is always the last 8th note rhythm before a chord change.
"using accompaniment strum #2" 
Page 1, basic 4/4 accompaniment strums 