Installing - dslake/WorldDownloader GitHub Wiki

How to install:

1. Open your minecraft.jar* with an archive tool like 7zip or WinRAR.
2. Put the class files you just downloaded in there. Overwrite if necessary.
3. Delete the META-INF folder if it exists in the jar file.
4. Close the archive and save if asked.
5. Done.

Note: You can find minecraft.jar on ...

Windows by entering %APPDATA%\.minecraft\bin in an Explorer window or in the start->run dialog.

Linux by opening ~/.minecraft/bin/ in a file manager of your choice.

Mac OS X by opening Library/Application Support/minecraft/bin in Finder.