just run the .jar file and click install. if sucess start Minecraft.exe then go to profile name "Forge"

Should find a folder that says "Forge"

it will automatically go to that profile for some people just ckick "Play" if failed enter Login Info

If already installed just copy and paste .zip or .jar files into C:\Users\AppData\Roaming\.minecraft\mods

if no file contained.It's that simple. Name it 'mods' or it wont work with forge :(