the 120v goes to the black wire of your power cord
a2 lamp goes to the black wire or center post of the socket and a2 of the igniter
com goes to the white wire of the socket along with white wire from the power cord and a3 of the igniter
a1 to a1 of the igniter
that just leaves the capicitor wich you should have 2 wires or terminal labeled cap where you can attach the capicitor either to by soldering to a terminal or by connecting wire.
the green wire from the power cord is just a ground you can attch it to the ballast box if your using a ballast box.