Push that chain way back up on the cord and out of your sight. Can't stomach it right now. Who needs that pesky thing - right now it'll just be in the way.
Notice the two leetle screws one on either side. One has the wire on, one needs it still. (When I say wire- I mean the two bundles of thin wire of your cord. There are several little wires but they are called "a" wire in the electrical world- (but I can't stop thinking of them as bundles, how and why I don't know. If any of that confuses you- don't worry about it. It doesn't effect us at all.)
Put each wire (well, you know what I mean) around in a clockwise "twist" behind the screw. This way when you tighten the screw down the wires (righty tighty lefty loosey) you won't work against you and try to break free from their connection.
Now- slip the black part of the plug over the wire.
(& PS I look very much like this only much cuter and if any one tells you different well they're dern liars and can't be trusted)