I used these guides to help me get the Clip 2 apart and found that my problem was a bad solder joint at the speaker connector. Apparently the manufacturer noticed it too because there was a (grease pencil) circle around the holes on the bottom side of the motherboard and their fix was to hot glue the connector to the board. I re-soldered the pins and it works perfectly.

I would imagine any small guage wire would make a good replacement. Like an ear bud wire or the like.

If no parts are required what are you replacing the speaker with?

What kind of battery is it? And where do you get a new battery?