I. Slide to top cover towards the front to take it off and loosen the four screws at the front cover of the camera.
II. Carefully remove the front cover from the main casing and put it aside.
III. Open the WebUI and check the live video. Turn the lense, until your area of interest is in focus. If you turn the lense clockwise, the plane of focus moves away from the camera image sensor.
IV. If you turn the lense counter clockwise, the plane of focus moves towards the image sensor.
V. After you adjust the focal point, carefully reinstall the front cover to the casing and tighten the screws again. Also slide back the top cover.