wifi adapter. How to solder an external antenna to it?

Question

Computer networks

Hello. There is such a USB Wi-Fi adapter.
I want to solder an external antenna to it, but I don’t know where to solder the center. lived, and where - the screen.
postimg.org/image/bkk0v5dz1
postimg.org/image/uuvmsbpb
Please tell me who understands (it is advisable to show it right in the picture, for example, circle the necessary contacts in paint and mark where to solder the center core, and where - the screen).
Thanks in advance.