If you don't know what software you need to use, let alone how to spell it, getting our permission is the least of your concerns.
It takes alot of practice and alot of time to make a mod of a game. I suggest you take up your own little trade like modelling or mapping and practice that on your own before even thinking of making a mod.
Milkshape 3D is a good starting program for modelling, someone else can probly direct you to a good mapping program.