I agree that he is capable mentally, but I call BS on the 30 to 40 min. Yes, YouTube will have a detailed video on how to do it and everything you need but there is always a bolt that some SOB engineer put in there that you cant get to.
I changed out the alternator on my 02 trailblazer that I used to have and there was that one bolt that took the perfect ratchet extension and a covering on an adjacent hose rubbed the hide off the back of my hand every time I turned the ratchet.
Its possible, but there will be a bunch of sweat, cussing, and bloody knuckles before he's done.