PE9 (aka Chinpak) is found on the posterior aspect of the front hoof, in the central depression.

The foot should be lifted and the needle inserted in the direction of the point of the hoof up to 1.5 Tsun deep
My Graphic
To find this point on the front foot, lift the foot from the ground and flex and extend the foot while you run your finger down the midline of the posterior aspect of the pastern, from the fetlock until your finger "drops into" a depression .

circle in the picture above indicates the point of entry of the needle and the arrow the direction of thrust towards the tip of the hoof. There is a considerable amount of dense fibrous tissue here into which you anchor the needle
My Graphic
Note that with the exception of PE9 (Chinpak) and KI1 (Haopak) all of the Tsing points are located on the coronary band of the hoof.

For the points on the coronary band, you should use a 13mm needle and beware that you or the attendant does not get kicked because it can upset some horses severely.

The trick is to hold the foot up off the ground, and press your fingernail into the point and maintain pressure for a few seconds. Then slip the needle in alongside your fingernail, and allow the foot to return to the ground.

NOTE: All coronary band points are located at the hairy/hairless skin junction.