ok i've been trying to play it for the past 2 hours and here what i've come up with so far:
first of all you need 0 delay and 0 reverb i think to keep everything from ringing together
second you need to use your pinky and/or ring finger as a string dampener at the same time u are tapping but without sounding the harmonics on the 7th fret

i know what your thinking, and yes it damn hard to do and takes a ton of concentration
third....you need a harmonizer hehe
if you can get the right hand position just keep beating it into your head like any other technique, practice makes perfect