Lift the motherboard off the base and flip it over to access the headphone jack. Make sure you have the right port; check that it's shaped for headphones to be plugged in, and not the charger.

There will be a total of five connections between the headphone jack and the back of the motherboard; desolder all five. See this guide for information on how to desolder connections.

You will need to resolder the new headphone jack back to the motherboard to replace it and reassemble the device; see this guide for information on how.

Remove the desoldered jack. It is now ready to be replaced.