Remove the two plastic screw covers below the inside phone screen.
Unscrew both screws using a Torx T6 screwdriver.
Pry off the screen front cover with a 3mm flathead screwdriver.
Pry off the speaker, which is glued onto the front cover, using a small flathead screwdriver.
Unsolder the black and red wires of the speaker from where they are attached to the base of the screen.
Obtain replacement speaker and solder the new black and red wires back to the base of the screen.
Apply glue to the back of the speaker and place it back in its original position.