The loudspeaker in the LG G3 (D855) is located on the bottom half of the plastic panel above the daughterboard and must be replaced with a new one along with the panel itself.
Power off your device.
Remove the back cover by lifting it upwards.
Use a fingernail or a prying tool at the marked notch to pry the battery out.
Remove the battery from its recess.
Remove Phillips #00 screws with 4 mm length.
Do not insert anything other than a thumbnail or a prying tool to avoid damaging the back cover.
Remove the plastic panel, which includes the loudspeaker, by gently pulling it away from the phone assembly.
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