Make sure you have a parking spot.
Put on your seatbelt once you're in the car.
Pull up forward from where you want to park.
Put the car in reverse.
Make sure there is no one behind the car using the rear view mirror.
Look through the side mirror and try to get between the lines.
Don't forget to look at both side mirrors.
Pull up again if you couldn't get between the lines the first time and repeat steps 4-7.
Once you have parked between the lines you have now reverse parked.