Hacks or "fixing" patches?
If the former:
http://www.romhacking.net/
If the latter I suggest a tool first and I do not have a link on hand:
ucon64:
http://ucon64.sourceforge.net/index.php (there are a few reworks and frontends as well).
Some hacks will include common corruptions things to something else, I have toyed with the idea of a massive PAR2 library as well.