These instructions are for third-party launcher, for instructions for the real launcher click here.

To install LiteLoader with a third-party launcher, you will need to locate the version JSON file which the launcher uses to configure your game environment, consult the launcher documentation to determine the location of this file for the launcher you are using.

Once you have located the version JSON file, make the following alterations:

{
    "name": "com.mumfrey:liteloader:1.7.10",
    "url": "http://dl.liteloader.com/versions/"
},
{
    "name": "net.minecraft:launchwrapper:1.11"
},
{
    "name": "org.ow2.asm:asm-all:5.0.3"
},
{
    "name": "com.google.guava:guava:16.0"
}
--tweakClass com.mumfrey.liteloader.launch.LiteLoaderTweaker
net.minecraft.launchwrapper.Launch

That's it! The next time you launch the game the launcher should automatically download the required files.