For one, don't waste your money, a TB on an N/A car isn't worth it...The stock one flows plenty...
If you are really wanting to get one though, the modification you need to make is you have to cut out the center section of the throttle body neck between the 2 bores of the stock throttle body are...if you take your throttle body off you'll see what I'm talking about...That center section won't let an oval blade open all the way...When I had my intake done I had the guy cut away that section incase I ever wanted to upgrade to a single blade TB..
Here's a picture of what mine looks like after that center part was cut out...