How do I install my wireless card driver offline

I have done it on Xubuntu 12.10 (Quantal Quetzal):

1. Download firmware-b43-installer and b43-fwcutter from Ubuntu, choose the target release version (I chose Quantal) and architecture.

   • Alternatively, if you have a Live CD or installed *Ubuntu of the same release with Internet access, you can do: apt-get -d install firmware-b43-installer and then look for both packages in /var/cache/apt/archives. Do not use packages from different releases.
   • Do not download from Debian. Being a derivative does not imply that they are compatible, and does not imply that Debian's packages are suitable for Ubuntu.

2. On the target machine, do dpkg -i b43-fwcutter* && dpkg -i firmware-b43-installer*

   • b43-fwcutter is a dependency of firmware-b43-installer, so it must be installed first.

I believe the package you need is linux-firmware-nonfree. http://packages.ubuntu.com/raring/all/linux-firmware-nonfree/download

Please download the package, transfer it on a USB stick or similar to the desktop of the Xubuntu machine. Open a terminal Ctrl+Alt+t and do:

sudo dpkg -i Desktop/linux*.deb
sudo modprobe -r b43 && sudo modprobe b43

You should be all set.