When remove left speaker, the Power switch cable broke :( How to fix?

Thanks but broke point is on the switch, to solder this cable, it seems must remove whole switch button, because I can't find solder point.

I found 2 screw on it, so I think it can be remove. And eBay sales this Power Button Switch.

but which screwdriver can remove it?

If the switch is not much, I would order in the switch then see what there is to it. That way you see what has to come out before maybe pulling too much out. Good luck

You can search"A1418 Power Button" on eBay, I can't give you URL, because this site detected it as spam.

I looked at the posting on eBay, the one from England, and the picture does not give much information. Not quite sure of your experience level tearing stuff apart, but if you have a good strong flashlight and a magnifying glass you should be able to see what those screws hold and what type heads they have. The iFixit toolkits have pretty much all the bits you'll need to conquer this project. Best advice is go forward and conquer. But I personally would not spend that much money on that switch if all that you did was bash the wire. Just take pictures at each step so you have a record of how to put it back together and when you're done you can even submit a guide on how to do it. Good luck and just keep focused.

As a sidenote, I did some research and it appears a lot of people have broken those wires. Normally that circuit is a simple push to momentary close that triggers the start cycle. The image that you directed me to almost looks like the disc battery is located on that same component. When you get it out please take a picture and posted on both sides and I will do what I can to help you through with it.