There are two screws on the rare case of the device. For the one shown in blue marker requires either an extended screwdriver or putting on a little pressure on a regular screwdriver.

Remove the two 9mm Phillips #1 screws from the rare case of the device.

If you cannot remove the screw with low pressure, do not use high pressure to remove it. It may cause a damage on the device case. Use an extended screwdriver instead.