Logitech speakers and computer speakers in general can appear difficult to open. But with careful examination you'll notice the speaker is held in place by small screws. You open up the Logitech speaker by unscrewing these screws and pulling off the plastic casing. Opening the speaker yourself will save you the time of sending it to a repair shop.
Unscrew all screws covering the speaker casing. Turn the screwdriver counterclockwise repeatedly to loosen each screw. Pull out all screws and place them where you will not lose them.
Pull off the plastic casing around the speaker. Pull gently the casing to avoid any electrical damage.
Unscrew the internal casing around the speaker cone. The Logitech unit will have an internal casing that holds the speaker cone in place. Unscrew the screws and pull away the internal casing.