How this guide became “Featured” is beyond me. Some of the pictures show him opening up the wrong end of the speaker, but most importantly the technique shown here WILL break stuff. The way the top/lid is made makes it impossible to open like this without breaking the structure.

It will however mostly go back together, so it is possible to do it like this, just know that it wont be entirely like before. From what I gather the rubber seals are positioned so that the speaker should still be waterproof after changing the battery.

I took a lot of pics of mine after I opened it, shown here: https://www.reddit.com/gallery/iqq59a