For both the microphone input and audio output, use a desoldering pump for all three solder points. Use the technique here for all of the soldering points.

To use the desoldering pump create a suction over the solder point and after the solder has melted press the button on the pump like shown in pictures.

If you are unfamiliar with desoldering pumps, please consult the iFixit Desoldering Pump Guide.