Some of the versions of how to install a package from the USB include commands to move the file, or find the file, etc, and it always says the file does not exist. I've tried putting the tar.gz file in several places on the USB, and no matter what I try, it cannot find it when I try to do anything. What I can't seem to figure out is what the next step is. So without internet, I looked into ways to install packages without a connection, mainly using a computer with internet connection (in my case booting into the existing OS X) and putting the package I need on the USB. I am tempted to take the HD out of the air and install archlinux with the HD plugged into my main desktop, but removing the HD without damaging the ribbon cables looks like a pain, so I'd like to keep that as a last resort. With only one USB port, the only way to tether from my phone is with a USB hub, and my phone doesn't seem to recognize that it's plugged into a computer so it won't give me the option to tether (not sure if it's the fault of the USB hub or something else).
Since it's an air, it has no ethernet cable. I'm trying to install archlinux on a 2009 Macbook Air (A1304), dual booting with OS X, and it needs b43-firmware for the wifi to work. Still had lots of trouble installing them in the various offline methods, finally found a wifi USB that worked and downloaded the packages I needed using wifi.