Download Forge and open it with WinRar or any Archiving program.
Go to the windows button at the bottom left corner and type in %appdata% in the search bar. (For Vista go to Run and type in %appdata%).
Now go to .minecraft and then bin, and open minecraft.jar(It's just minecraft for most people) and open it with your chosen Archiving program.
Now to install Forge you need to DELETE META-INF, then open Forge Universal and drag and drop all folders and classes into the Minecraft.jar. (I don't delete the META-INF, but it's optional.)
Run Minecraft (but don't exit out of Minecraft.jar (No one say this is wrong, because I've tested it!).).
Login and it should install Forge.
Once Forge has finished it should say in the bottom left corner of Minecraft 4 (or 5) mods installed(or active), if it does, then you've installed it right!
Now to install my mod, you go back into your Minecraft.jar and drag and drop all files and classes in the Archive into the Minecraft.jar!
Now you've successfully installed Commands For Minecraft 1.4.6!
NOTE: This is not meant to be a copy of Single Player Commands, as (but) it was inspired by Single Player Commands!
NOTE: Requires Cheats to be on!
/flyon --Enables player to fly around like in creative mode!
/flyoff --Disables Player Flying!
/gm (0,1,2) --Changes the players Game Mode
/damage --Makes player immune to dammage
/i ZxBloodZ 1 10 --Gives the user ZxBloodZ 10 Stone!