Watch the Need to Stretch online guitar lesson by Brad Carlton from Chord Studies: Power Chords Vol. 1
These are four-voiced power chords that are utilizing some stretch voicings. Our first chord is A5 and not only do you want to make sure your notes come out clear, but you need to watch your intonation. Then we move everything down a fourth by simply going to the middle four strings and you've got your E5. The last chords are using voicings and fingerings that should already be familiar to you, so they should be no problem.