Here's a quick tutorial on how to install forge mods on minecraft 1.5.2 and under
- Download Minecraft forge for what ever version minecraft you have (you can find this by opening minecraft and it's on the bottom left corner picture below).
- On windows 7 or below click on start then type %appdata%
- click on roaming
- click on .minecraft
- open bin
- Open minecraft.jar with winrar or 7zip (preferably winrar)
- delete META-INF
- open forge with winrar or 7zip
- highlight everything inside it
- drag it into minecraft.jar wait for it to finish
- create a mods folder inside the .minecraft folder go up from the bin folder
- copy and paste a forge mod for your minecraft version in there
- run minecraft and unless you want your mod to stop working (forge will be uninstalled) don't update Minecraft.
IMPORTANT you must start with a clean minecraft you can do this by opening minecraft click on options click force update done then launch Minecraft.
I haven't got how to do this on 1.6.1 and over because I haven't yet figured it out myself!