I have loosened the two screws and I am pulling down the back panel as hard as I can, also tried moving it from side to side but still it does not come off. I pried the sides with a tool and after looking carefully with a flashlight I noticed two small metal clips in there. Do they need to come off? The stubborn back panel is driving me nuts here; I am afraid to pull any harder as I am pretty sure that something is going to brake.