---ModLoader is nedded---
1. Go to the ".minecraft/bin" directory and backup minecraft.jar
2. Using 7zip or equally capable archive viewer open minecraft.jar
3. Delete the META-INF folder (if on a MAC *only* delete the Mojang_c files)
4. Copy ALL the ".class" files contained within the mod to minecraft.jar, replacing the existing files or copy The .zip in ".minecraft/mods" .
5. Enjoy the mod.