Repair Right Speaker/driver on my WH - XB900N; not working

After opening it I found out if I press (with something like a pen or screwdriver) on that mini red wire running on the driver (like in the picture) it suddenly plays music. that's why I want to open this thing up to access the speaker/driver. I saw a video where someone opened it up, but I don't know how, because I already tried it with a hairdryer and a scalpel but wasn't able to lift it even a little bit. here the video where someone to it apart: https://www.youtube.com/watch?v=lm7N81Fw...