If you could do this, you would be my hero! I am addicted to blitz 2000 for n64. I've been looking everywhere, and I could not find any hacking tools. I have no concept of hex editing either or I would have done that a while ago.
I mod nhl 94 with editors, I'm pretty sure if you needed help you could go over to their website. (http://forum.nhl94.com/)