Step 1: Fit the Top Strap
 Unbuckle the harness and place it over your dog's head with the front strap facing towards you. 
 Adjust the top strap so the O-rings sit above and behind your dog's shoulders.

Step 2: Fit the Bottom Strap
 Adjust the bottom strap until you can only fit 1-2 fingers between your dog's body and the harness.

Step 3: Fit the Front Strap
 The front strap should sit horizontally and the d-ring should remain in the center.

Now, enjoy your walk :)