Installing Minecraft Mods is a very simple task. Just follow these steps listed below:-
Find the .minecraft folder on your server.
For Windows Vista and above, type the following in Start Search box:-
Note:- For Windows XP and below, you have to type the command in Start -> Run
Note:- In some versions of the Windows OS, the following needs to be typed instead of the command above:- %AppData%\Roaming\.minecraft\
For LINUX, type the following:-
For Mac, type the following at the terminal:-
Take a back up of this minecraft folder and save it with an appropriate name (say, minecraft-backup)
Download the mod to be installed.
In the minecraft folder, find and open the bin folder.
Inside bin you’ll find a minecraft.jar file. Open it by right clicking on it and using a suitable archive manager (like WinRar or 7 zip).
Open META-INF and delete the .sf and .dsa files. Leave the manifest.mf file untouched.
Open the mod file. This file, which will most probably be an archived one, can also be opened with the same archive manager that you used previously. Check if there are any ‘ReadMe’ files or instructions for using the mod. This is important because different mods might have different settings and configurations.
Drag and drop all files from the mod file into the minecraft.jar file.
Start Minecraft server.
In case the mod causes any damage to your minecraft server, revert to the backup that was taken.