http://www.img2.9minecraft.net/Tutorial/Minecraft-Forge-Installation.jpg

For Minecraft 1.6.x

Step 1:

Download and run the new Minecraft launcher at least once.

Step 2:

Download the latest version of Minecraft Forge API installer, choose the installer option.

Step 3:

Run the downloaded jar file. It will open a menu as shown below:

http://www.img2.9minecraft.net/Tutorial/Minecraft-Forge-Installation-1.png

Step 4:

Press OK, and this will appear:

http://www.img2.9minecraft.net/Tutorial/Minecraft-Forge-Installation-2.png

Step 5:

Open the Minecraft Launcher and select the new Forge profile

http://www.img2.9minecraft.net/Tutorial/Minecraft-Forge-Installation-3.png

Step 6:

Enter your username and password and launch the game at least once.

Step 7:

Minecraft Forge will now have generated its folders in %APPDATA%.minecraft. Place mods into your %APPDATA%.minecraftmods folder as you have in the past.

Step 8:

Run from the Minecraft launcher through the Forge profile and profit?!?!

For Minecraft 1.5 and below

  • Open your Minecraft launcher.
  • Open the “Options” menu near the “login” button
  • Use the link in the Options menu to open the .minecraft directory
  • Navigate to the bin folder.
  • Download the latest version of Minecraft Forge, choose the universal option.
  • Open minecraft.jar and the Forge version you downloaded with appropriate archive software. (i.e WinRAR, 7-Zip)
  • Drag all contents from Forge into the minecraft.jar
  • Delete the META-INF folder from the minecraft.jar
  • Close both minecraft.jar and Forge download.
  • Go back to the .minecraft directory.

For Windows users, you just have to run install.cmd. If you’re on linux, you need to copy files and apply patch manually for now, A install.sh for linux users too is on the way.