Note the location of the internal speaker cable connection. Note the routing of the internal speaker cable. Disconnect the internal speaker cable from the system board. See "Locating parts on the system board".
Use a blunt instrument (such as, the top of a ball point pen) to disengage one of the internal speaker locking tabs (2) and slide that side of the speaker (1) upward enough to keep the locking tab disengaged. Then disengage the other internal speaker locking tab and slide the internal speaker upward until the speaker is released.
Remove the speaker and speaker cable from the computer.
Route the new speaker cable and then position the new internal speaker tabs (3) into the metal speaker slots and then push the internal speaker downward until the speaker locking tabs snap into position.