swapping a 2wd into a 4x4

so i have a 1994 ford f150 thats a two wheel drive. now where i live and the utility in a 4x4 i wanna know if it would even be possible with little to no modifications to swap it. i know ill need the differentials and.. yeah no thats as far as my knowledge goes as of right now. i wanna know if its easily possible or if its an expensive pain in the ass, though im probably doing it anyway cause i also intend to never let that truck die.

yes i know youtubes a thing, i dont wanna listen to "HEY GUYS TODAY WERE.." 10 times in a row from different people that do it differently and make things confusing