I don't remember exactly, I thought it had screws when I got mine. Wait, yes, it had two screws on the back. If there are none visible, just stick a flathead in, turn it 90 degrees, repeat around the case, and pry it open.
Also, there is a power cable, but it has the head that goes like it has those 3 plugs, then the other cable has the male plug, and the other end of the male cable has 2 wires.
there is supposed to be a plug at the end of those wires right?
yellow is av1, white is av2. red is power. the male jack for power with the wires coming out is meant to be like that, so you can wire it into a car system.
I think it automatically goes to the second if nothing is coming in the first, so you have to turn off the first input and it will automatically go to the second. It's so one input will be the rear backup camera, and you can use an av device as well if you like.
Just pry it with the screwdriver.
I'd imagine black is the negative, but once you get the thing open look inside and see if the colorcoding is the same, because the mobo has markings on it for V+ and ground.
i found that the wire with a white line is the positive, works fine for me, if you doubt it, just multimeter the balls of it knowing that on the male plug, the exterior metallic part is ground and the inside is positive, as always