First of all we should remove the tray from the cards.

Remove the 10 hexagonal screws (H1.3) that surround the phone.

With the help of a flat tool we will unhook all the edges of the casing.

To remove the loudspeaker we will have to take off a lid that is in the lower part of the intermediate casing, once it is detached we will be able to disconnect and take off the loudspeaker that we are going to replace.