I am no expert either But:
1 trade the iso for a disc (unless you are A thief and penny pincher)anyways you will need extensive hacking to do that anyways
2find downloads for homebrew channel or whatever loader you choose.
3 place programs on wii and gecko os on a sd card (downloads for all of the above are on meowmix wiki)
4get your codes
5place your codes in the corect directory (find the fighter folder, look in pf in the private folder in your sd) apply the file patch code on it place in your wii boot brawl through homebrew and you are set.
Find more complete instructions on the Meowmix wiki I am a bit rusty myself

My name seems to have a dual handle I am a Mac and my trash can is corupt after attempting to delete somthing

And with gecko in a folder Boot elf does not detect it

  I am using a stacksmash method for hacks (like the one included for brawl minus or bbrawl) i have started with bbrawl. I unzipped it opened the file and placed in sd but gecko os does not detect codes (gecko is only detected when it is in root of sd but when code are placed there the boot elf is not even detected and the game does not even freze or screw up) Help?