the first step is to pop all the plastic retainer tabs out of place, so that the back panel plastics are just hanging loose. then, place your thumbs against the locking tab, and wrap your fingers around the plastics. work it left and right, and you should be able to finesse the plastics off the lock tab without any damage. It make take some force, but if you're careful, you wont break anything.
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Electricity tastes good. No, seriously.