I have basically the same saber (Dark Shock with sound) so I can help. Unscrew the pommel. You should see a small speaker. The speaker is attached to the bottom of the battery pack. You might have to tap the hilt to get it to come out. It took me a little bit to get it out, cause I didn't want to damage the speaker. Hope I could help!

Bet that's a SWEET looking saber!!!