widescreen to fullscreen?

i have an xvid movie i created from my own dvd's and it is in widescreen b/c thats the only type of dvd they make of that movie and i was wondering how to change it to fullscreen style (4:3 i think?) thx all

 

widescreen=instant artistic

i think it involves resizing and cropping.
let me calculate.

 

yes but how would i resize it and crop it and all that stuff with having to re-encode it differently?

 

anybody wanna tell me how =) like precise directions