Okay, hope this helps some people!!
1.) Open text edit, and write the game ID at the top of the page. Underneath, write the game name.
2.) Go down like two spaces, and then write the codename, and underneath that, write the actual code. It should look like this:
WR9E
Megaman 9
Infinite Items [hetoan2]
00D4101E 00050009
Infinite Lives [hetoan2]
00313FE4 00050009
Infinite HP [hetoan2]
00313F4F 0000001C
etc.,etc.,etc.......
Thats how i think its done. After you finish typing all the codes you want, make a folder on the root of your SD card called "txtcodes". Drag the txt file you made to this folder.
Then, get the cheat manager app here: http://www.wiibrew.org/wiki/CheatManager. (http://www.wiibrew.org/wiki/CheatManager.) Put it in the apps folder, and then launch it through the homebrew channel.
It should locate the txt file on your sd card, just press A on it. Press + on the codes you want to apply, and - on the ones you don't want. When you're done, press 1 to generate a GCT file out of you txt file. Go back to the homebrew channel, and launch gecko os. Load whatever channel you have the codes for, and they should apply. I think thats it. :D
No, I have a better way !
If you are using Mac 1.4.X or 1.5.X -> Use DarWine !!!
1) 1.4.X user only -> Install X11 ! (1.5.X user have X11 automaticaly)
2) http://www.kronenberg.org/darwine/ (http://www.kronenberg.org/darwine/) (Download)
3) Install... (drag DarWine to Applications folder)
4) Download CodeManager
5) open CodeManager
6) DarWine start the debbuger
7) have lulz with your codes