If you are using CorePlus, the
wifi.tcz is already included in the iso.
Boot to GUI and click the wifi icon in the bar (wbar) below.
Or you can switch to CLI and run
sudo wifi.sh
If you are NOT using CorePlus iso.
Run
tce-load -w wifi.tcz
tce-load -i wifi.tcz
sudo wifi.sh
All the pre-compiled firmwares are also included in the CorePlus iso, and will be loaded by default.
Note that you don't really need all of them, just the one that fit your hardware.