inner fender wells on 98 s10

i have a bagged 98 s10 that still has the front and rear fender wells & i was wondering how much trouble it is to cut out the inner fender wells and what can be completely thrown out and what needs to be relocated?? right now it's sittin on the 04 16 in. zq8's with a 50 series tire and i'm about an inch from frame but i plan on going with some 18's in the near future and wanted to just go ahead and get all this shit out of the way before i get the wheels. i understand the rear is simple. i already have the bed cut out to the fender wells; they're all thats left to do the rear. all help is appreciated!