@bkmac66 use something like [https://www.youtube.com/watch?v=nKt-r9YvO4g|this video] as your guide. New batteries are readily available. Use a vendor that appeals to you. Remember that some places do not ship this type of battery across countries etc. so stick with something regional.
While you work on your speaker, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.
Repair is War on Entropy!