How to use minecraft forge on a mac?

You need to open the minecraft.jar by adding.zip at the end "minecraft.jar.zip" the when it asks you if you want to use.zip or.jar just click.zip A zip file will appear and click on it, a folder called minecraft.jar will pop out open it. Next get the forge folder and open it, coppy all of the files in the forge folder into the minecraft.jar folder and click replace all. Then just launch minecraft and let forge load