The opposing screws on the rear mount adjust windage. Move the scope in the direction that you want the POI to shift. Loosen one screw; tighten the other. Make sure both are tight once zeroed. Elevation is adjusted via the larger knob on top of the scope. Once zeroed, you can loosen the three screws on top of the knob to adjust the outer ring to 100 (or what ever the range the rifle is zeroed). The small oblong device on top of the larger ring adjusts focus. The small knurled screw locks elevation in place.
I find these repros to work pretty well. One issue is the lens-locking ring on the front lens tends to loosen with recoil. Fairly easy to fix. Second, is the locking screw block tends to loosen with repeated use. This can also be fixed with minimal effort.
Have fun