Yes, opening it is tricky. It has to do with the HDMI connectors, they stick out quite a bit and hold the whole thing together very tightly.
Once you've removed the four screws, you want to take a wide flat edge (like a butter knife) and shove it into the seam where the HDMI connector is on the *input* side (the side with the LEDs). There is a groove cut in the plastic which allows the connector to slide in and out through its angle of rotation. The opposite side should stay in place until the LED side is free of the case. You can't remove the device from the other side, the 3.5mm jack and HDMI connector will interfere and you can damage the board by pulling it apart from that side.
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