first strip the entire interior except for the drivers seat teh steering wheel the stereo and the instrument cluster.
Then you need to cut 6 holes in the hood and run pipes through them to allow for a better breathing exhaust.
Then put si stickers all over it.
thats a good start, if you need more info SEARCH....lol man i'm just playing, by searching you will the best questions along with the best responses.
Also check the FAQ section on celicasupra.com.