Now that every thing is done make sure to test the board and see if it works, if so then carefully put the circuit back in the rubber casing. then you...
As some of you might know that the packaging on these flashing teeth toys say that the batteries are non-replaceable. I'm here to tell you that they are wrong.
Step 1: Getting the circuit board out
To start you will need a sharp razor blade knife (please use discretion while using sharp objects suck as razor blades). Next take the knife and make a cut big enough to get the small circuit board out.(see photos 2 and 3 for reference).