This exercise is from the Core Skills section on pinch harmonics.

Ensure your amp is set on full distortion with maximum high end (treble). Also make sure you are holding your pick as shown in the previous video.

Fret your finger on the 7th fret of the G string as shown in the ActionTab. Now find a good pinch harmonic 'sweet spot' along the string - as near to your pickup as possible. Keep picking around the string as shown in the previous video until you hear a definite sweet spot. There are no frets around here, so finding the best location for your pinch harmonic will take a little experimenting.

When you feel you have located the sweet spot, execute the pinch harmonic pick. Remember to hold your pick so that the tip of your thumb sticks out past the very edge of the pick by a fraction. Holding the pick this way means that when you pick the string (downstroke) your thumb will follow and also hit the string almost instantly afterwards. If you do this correctly, you will hear either a harmonic or a dead note.

If you keep getting dead / muted notes then try this pinch picking technique slightly further along the string (preferably over a pickup) until you find that juicy harmonic.

You can hear the high-pitched sound of the pinch harmonic in the ActionTab. Now you have located where to do your pinch harmonic on the string, we can look at getting the same effect!

Hit the pinch harmonic again - and bend the note on the 7th fret. Start the bend instantly, but bend it quite slowly. This drags out the pinch harmonic and gives you more control over the sound. Keep practicing until you get that squeal!

It is actually easier for most people to learn by bending the pinch harmonics at first - the sound is more defined and easier to sustain when bending them.