If you don't already have one, get an ethernet cable to
connect the two Macs. It doesn't have to be a "crossover"
cable since modern Macs autosense.
If, on the other hand, you have both set up to access the
internet via a router to, say, a cable modem, you're all
set.
Go into System Preferences, Network. Our settings are
Automatic/BulitIn Ethernet/AppleTalk and check the AppleTalk
box. But we have PPC Macs. I seem to recall Intels don't
use AppleTalk, but memory is so iffy at my age.
Then to the "Sharing" prefpane. Check "personal file sharing"
under Services.
Do this on each Mac.
In Finder, click the big blue ball on the top of the left
panel (Network) on one Mac. At this point you should see the
other Mac as a potentially shared device. Connect to it with
THAT MAC'S login-ID and password, so you log in as the owner
and can see everything on its HD.
Drag the file from one HD to the other.