Making Zombie run faster? (Half-Life) Thread

Hi, i want to make a mod for half-life but im tired of the zombies walking so slow. I want them to be really fast and scary. Someone told me that it had something to do with animations and i should leard to make models. He didn't specify exactly what i needed to do (or change). So now im looking for more solid instructions. If anyone know how to speed up the zombies i would greatly appreciate it if you told me. Or someone maybe knows any good tutorials on how to do it?

modeling is not my expertise area but
i think it has something to do with editing the .qc file