Delete META-INF!
Install Forge ModLoader BEFORE you install Swords of Israphel!
Drag all the files inside Minecraft.jar.

~ Twinklez

[This mod has source code.]
[Visit my PlanetMinecraft page to find it]

IMPORTANT:
THIS MOD REQUIRES FORGE MODLOADER

Forge Download [1.5.2]:
http://adf.ly/673885/http://files.minecraftforge.net/minecraftforge/minecraftforge-universal-1.5.2-7.8.0.684.zip