Watch the Voicings without the Root online guitar lesson by TrueFire from Play Acoustic Guitar 8: Advanced Techniques
Voicings without the Root - Harmony Applications: 3 is a video guitar lesson presented by Massimo Varini and is sourced from Pop Guitar Survival Guide.
There's another way to "easy play" chords with a lot of extensions - use triads. Look at this - In pop music, mostly, you're never alone. There's a bass line, or piano, or synth, and they play the root of the chord. So, if you play just a part of the chord, the result is the same. Playing in a pop arrangements allows you to think about parts and not only about guitar. You're not forced to play all the notes of the chords. If the bass is playing C and the piano is playing a Cmaj7/9, you can play just a simple G triad, or a Em7, or a Em triad. The result will be the same! Another example is with a dominant chord: In pop music with reggae influences in very high treble parts it's fundamental and very very important to know this! This allows you to play good parts!