It looks like the yoke is probably okay. If the shoulder pad attachment point is below the tops of your shoulders (traps) and down near the top of your shoulder blades or a touch lower you are probably okay where you are.
Loosen load lifters way up, tighten shoulder straps until they wrap nicely up and over the shoulders then snug the load lifters.
Make sure you adjust load lifter pull point to at least the top of or better slightly in front of the top of the shoulder.
Load lifters should be loosened before taking pack off or before putting pack back on. Once the pack is on adjust load lifter tension. If you leave a bunch of tension on the load lifters when putting the pack on you run the risk of the shoulder pad bunching up.
If your preference is to loosen shoulder straps before taking a pack off loosen the load lifters first, then the shoulder straps. Putting it back on is the opposite. Tighten shoulder straps then load lifters.