I believe this is what you're looking for:
http://gbatemp.net/threads/modify-any-wii-4-3-below.171901/
It looks like it's become unstickied and I looked through about 9 pages and couldn't find it but I remembered I had linked to it in another thread so I found it that way.
I'm not sure if it was unstickied on purpose because it's no longer relevant or if was just an oversight.
Perhaps a Mod would be so kind as to explain the reason or replace it as a sticky if it was in fact an oversight.
Smash Stack and the other hacks only work if you have the specific game. Letterbomb is much easier to use and doesn't require a game to work. You don't have to muck around with hacked save files and boot a game and do a certain task for it to work, you just load the files on the card, click on the message board and navigate to the red envelope and click it...the hack begins to run and you didn't spend 5 or 10 minutes getting there.