how de heck does he do that? speedrun remake

[Megaman]

http://www.youtube.com/watch?v=4cTdrSyBhs8&feature=related

telling to my girlfriend because she has my gamecube and remake! :)

[Birkin]

Came across this video ages ago. But to answer your question, if you bothered to read the description, it says hes using an Action Replay.