Untar it to a directory, open konsole, su to root and cd to that directory. Then type
(if infact it has a capital I and not lower case...case must be correct). That should intall it or at least start the install unless it errors out. .ko files are modules that can be loaded into the kernel. There may be instructions near the end of the install that tells it what to do or it may actually place instructions in the /boot/loader.conf to load it on boot.