1, turn the power off
2. open the switch, assuming it's single pole ( it only has 2 connections)
3.in the switch box there should be 2 black wires and 2 white wires and possibly 2 bare copper ground wires.
4. connect the black wires to the switch, connect all white wires together using a wire nut, twist the copper ground wires tightly together and connect one ground wire to the green switch ground connection.
4.put the switch back in the wall and turn on the power.
FYI, a light can pulled off any duplex outlet regardless of where it is in the run. If it is in the middle of the run you will find 3 of each black, white and copper wires in the box. If at the end on the run only 2 of each. Just make sure the blacks are all connected to the copper colored screw side of the outlet and whites to the silver side. (coppers to the green if you have them)
Good luck
