Below is a drawing of the Top Harness noting where it was designed to be positioned on key body parts, along with where the closures and adjusters are:
Blue = Closure.
Pink = Slide Adjusters.

Don’t worry if it’s not in the correct position when you first pop it on, you may need to do a little wiggle to get in place. On the hips, waist and leg straps, you will find sliders where you can adjust the size to suit your body shape. Once you have everything in place and it fits to your comfort, this is now sized personally to you
and it will be easier and quicker to get into next time.