Use the wrench to remove the NG regulator on the grill. Screw the propane regulator in its place.
Unscrew the control panel from your grill with the screwdriver and lift the panel away. Unhook the burner from the control knob assembly under the panel. Slip the propane orifice fittings over the control knobs, using the wrench.
Tighten the propane burner orifices over the regular NG orifices with the wrench. Slide the burners back into the control knobs.
Unscrew the old NG hose and connecter from the grill and attach a new propane hose and connecter. Tighten with the wrench.