mod for front/back bumper

what mods are we lookin at that i would have to under-go to fit a CRX front and back bumper to my sedan 91 ? Jus wonderin cuz im finished pickin out EVERYTHING inside and out and i want to make sure i know the amnt of work im gonna be doin. I got everything picked out, besides the really small stuff anyone can add when ever they want type stuff. Well any pointers / help is appreciated. Thanks ! ~