1990 toyota celica st 3sgte swap(???)help

Hey i have a 1990 toyota celica st i want to do a 3sgte swap on but i dont know where to start does anyone know what ill exactly ill need ??and if i have to make any modifications to the car and if its safe ? please contact me as soon as possible its also a 5 speed manual (3237424380) i dont have the engine yet but i might get soon i live in california also