Remove the two 2.5 mm Phillips screws from the back of the power switch mechanism.

You can then push in on the power switch (on the exterior of the iPad) to push the mechanism's internal metal plate loose.

You can then peel the PMV cable free from the iPad's case, working backwards from the power switch towards the mute switch.

Lift free the small metal frame piece supporting the mute and volume switches.

Note: The photo shows the mute and volume switch frame being removed before the rear camera and power switch; this is possible but it's probably best to start with the power switch first.