It is possible, but it’s not that easy (for me) and you are definitely risking your PB in the process. I’ve done this on a V2, but not a V3. The antenna wires are ridiculously small and difficult to solder. Especially with my gorilla hands and crappy soldering iron. It does improve the signal, but like @zranger1 said - there are variables like antenna cable length that come into play. I initially did this for an outdoor install and all I had was a metal enclosure. In the picture you’ll see the original, where the cable had broken (pulled a little hard on it when removing from the enclosure). Then you can see where I attached a longer antenna cable. Also, you can see the before and after for signal strengths (my SSID = Stoneage).
Here’s the tutorials I used when I did this.
and