First I tried the first option:
pkg_add -r virtualbox-ose-additons
After that appeared to complete, nothing else was mentioned about having to configure anything else and nothing changed even after a reboot.
So, I tried your second command but I got an error about not having the required kernal sources so I found this page:
I followed the instruction by doing this first to get the newest files (or so I thought)
portsnap fetch update
That loaded a bunch of things.
Then I tried the make install clean command again and the command line is still saying:
===> virtualbox-ose-additions-4.0.12 requires kernel sources
*** Error code 1
Stop in /usr/ports/emulators/virtualbox-ose-additions.
In the meantime (thinking I had them installed for some reason) I did change things in the xorg.conf but I have not yet changed anything in the /boot/loader.conf file as directed (and the other requirements it states).
How am I supposed to get these kernal sources installed in an easy non-expert programmer manner, if there is such a thing?