How do you install Minecraft mods on a Mac?

I've seen videos for Minecraft mods which add features like oil, pipes and guns. Where can I find these mods, and how do I install them on a Mac?

2 Answers

1. Download the .ZIP file
2. Extract it to some directory.
3. Go to the directory you just created.
4. Open a new Window
5. Go to ~/Library/Application Support/minecraft/bin
6. Look for a file called minecraft.jar
7. Rename that file to minecraft.jar.zip
8. Unzip it
9. Drag all files ending with .CLASS into the minecraft.jar FOLDER
10. Delete the META-INF folder.
11. You're done!

This video is fairly old, but installing mods hasn't changed since it was made:

The mod pack

The instructions

A tutorial for general mods: