Unless the phone supports customized casings, which I'm not sure if it does (?), you're going to need to take it apart manually with a T6 screwdriver. You will then need to carefully take apart the old housing and put the new one back on, screw it back together and that should be the job done. If however it does support custom casing, the cases should be fairly robust and not so easy to remove, but obviously possible. Just take the previous case off and clip the new one on
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