How to install API Minecraft Forge Step by Step

For Minecraft 1.6.x and above:
Step 1: Download and run the new Minecraft launcher at least once.
Step 2: Download the latest version of Minecraft Forge installer, choose the installer option.
Step 3: Run the downloaded jar file. It will open a menu as shown below:

Step 4: Press OK, and this...
How to install API Minecraft Forge Step by Step - http://www.8minecraft.org/how-to-install-api-minecraft-forge-step-by-step/