plug the speaker output of the amp into the 4 ohm mono input of your cabinet. simple as that. however, as YJM already pointed out, your amp puts out more power than the speakers are rated to handle, so you do run a slight risk of cooking your speakers if you push them too hard.
as for the 400 watts / 60Hz thing, ignore it. it's probably just indicating how much power the amp consumes from the wall, as 60Hz is the frequency at which the AC in the wall is in the US.