My lower chain &tensioner was replaced now it only spins when I try tocrank it. on 2000 Ford Explorer

Is my timing off? I have everything apart and need to fix this myself. Do I have any hope? Or did this guy leave out a step?

Asked by for the 2000 Ford Explorer
do not attempt this yourself. you will cause more issues than you can believe. this takes a good mech like 12 hrs so its out of you ability i think
small chance of success? no faith from my fellow man? my favorite kind of odds. my good man, I accept your challenge. if you can give me any kind of advice, I would appreciate it. have no intention on troubling you, though. unless you dont know how.