I want to use the mod and I am having problems with it, I saw a video about how you are supposed to put all the files into the minecraft.jar file and from what I can tell all it does is replaces the files allready in the jar file, I followed the video and now Minecraft crashes.

here is the error I get

Mods loaded: 1
ModLoader 1.2.5

Minecraft has crashed!
----------------------

Minecraft has stopped running because it encountered a problem.




--- BEGIN ERROR REPORT 9f578458 --------
Generated 6/17/12 12:26 AM

Minecraft: Minecraft 1.2.5
OS: Windows 7 (amd64) version 6.1
Java: 1.6.0_21, Sun Microsystems Inc.
VM: Java HotSpot™ 64-Bit Server VM (mixed mode), Sun Microsystems Inc.
LWJGL: 2.4.2
OpenGL: ATI Mobility Radeon HD 4250 version 3.2.9751 Compatibility Profile Context, ATI Technologies Inc.

cpw.mods.fml.common.LoaderException: java.lang.ClassCastException: mod_MinecraftForge cannot be cast to cpw.mods.fml.common.modloader.BaseMod
at cpw.mods.fml.common.modloader.ModLoaderModContainer.preInit(ModLoaderModContainer.java:114)
at cpw.mods.fml.common.Loader.preModInit(Loader.java:235)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:593)
at cpw.mods.fml.client.FMLClientHandler.onPreLoad(FMLClientHandler.java:193)
at net.minecraft.client.Minecraft.a(Minecraft.java:382)
at net.minecraft.client.Minecraft.run(Minecraft.java:735)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassCastException: mod_MinecraftForge cannot be cast to cpw.mods.fml.common.modloader.BaseMod
at cpw.mods.fml.common.modloader.ModLoaderModContainer.preInit(ModLoaderModContainer.java:107)
... 6 more
--- END ERROR REPORT 9cb37797 ----------

install manually and do not use mod managers to install mods until this is sorted out!