Prying the battery out is HARD! and VERY dangerous. I tried using a flat head screwdriver, put it under the battery and twisting the thing out. DO NOT DO THAT!! as it can punch a hole in the battery if you twist it too hard. I had a small smoke coming off by doing that and was lucky enough it didn't burn. Using isopropyl would be an ideal solution. But to bad I can't find that around here :(.

[DO THIS ON YOUR OWN RISK] What I ended up doing is using the screwdriver to gouge the underlying glue out as much as I can on the side (about 10%) and use fingers to pry it up. Good luck!

See the yellow/orange circles? I thought I already remove it but it turns out I only remove the top screw. There's actually "another" screw in the "same" position, which is in disguise because it looks like a hole. It needs a rather small flat screw head to remove. I kept pulling the circuit board out but couldn't because I didn't know it. Be careful!