Hi,

Here is a link to the service manual for your laptop.

Scroll to p.95 to view the necessary pre-requisite steps and then the procedure to remove the speaker assembly.

Also on p.95 you'll find the HP spare part number for the assembly (730798-0010).

Search online using the part number only in the search box of your browser, to find suppliers of the part.

Hopefully this is of some help.