I don't think you have to cut anything to fit them...but even if you did, it's really not hard to cut something with a 30 dollar dremel from wal mart and a few cutoff wheels

it would be easy to see what needs to be cut when you go to install them. I can promise you, it's not going to be something that you'd see from the outside anyway. I modified my front bumper to fit a stillen lip, it's easy to cut through with a dremel. I've also cut 1/4" steel plates with a heavy duty dremel wheel. Harder to do, not impossible, but definitely fun.
I'd say start by contacting godspeed directly and asking this question. When you get the answer, post it up here for future reference. And for my reference since i'm interested too.
If you don't have a dremel;
The beauty of it is, you can buy/use the dremel from walmart, buy cutoff wheels for like 5 bucks, then return the dremel when you're done. You don't know how many times I've done that when i was 16.5yrs old with no cash just fuxing s*** up. Buy it from a department store, not a hardware store....better chance of getting your money back when you return it seeing as they don't realize you can actually do this and get away with it at walmart.