The first step is to remove the earphones from the rack. It's very easy because they are only clipped in. Put one finger between the rack and the phone and slowly pull to remove it.

You should also remove the protection pads for further steps

With the help of a flathead screwdriver remove the blue case that sits upon the connectors. Be careful with that step and lift it from both sides bit by bit

Notice some sort of glue patch between the connectors. DO NOT TRY TO REMOVE THIS GLUE as it protects two very small wires that take the signal from the connectors to the earphones on the other side.