y2kferari

So I had my battery light come on yesterday. So assumed my alternator needed to be replaced. SO I brought it and got rebuilt, they said nothing was wrong with it, but the bushing could use a replacing, so I got it replaced. Came back, put it on and cranked it, same battery code. So I checked under the hood, my crankshaft is not turning at all. But when I got under there, and I could turn it by my hand, so I was like wtf? Called my mechanic, who did my motor swap last week(i went with a d16z6 again). He said that if I can turn the crankshaft with my bare hand, that the keyway for my shaftshaft sheered/broke. So I could buy another one, take the 17MM nut off the end of the crankshaft, take the pulley off and there is a key in there I need to replace and that will be it. Is there any other steps that need to be done? I usually would not question my mechanoc, but he doesnt specialize in hondas, and he said I should be able to get one from autozone(which they dont carry, or any other parts stores, I will get one from honda tomorrow). SO, have anyone dealt with this before? any details would help.