At the back of the control valve where the water lines are connected, most of our water softeners and backwashable filters have 2 ‘paddles’ that are sticking up. To place the system in bypass, use your hands and give both of them a 1/4 turn so they are lined up with one another. They will likely be very stiff and hard to turn so you might need to put some muscle into it. If you use a small pair of flat pliers, be careful you don’t damage the paddles or turn them further than a 1/4 turn.