You can take the wireless interface down using the command line.
Open a Terminal window, and enter:
You will get a list of all of the network interfaces. Your wireless will likely be called
wlan0, and you can corroborate this with the information listed, such as the
In Terminal enter:
sudo ifconfig wlan0 down
You will be asked for your password, in order for this command to be run with the permissions needed. (if you don't have the permissions, you will be warned so.) This assumes
wlan0 was your wireless interface.
and you should see
wlan0 (or your interface) has been labelled
To reverse this, enter:
sudo ifconfig wlan0 up