The manual to which I think you refer includes instructions about what goes together in what order, what lubricants are used, what torques are applied to the fasteners and in what order, what clearances and dimensions should be measured in contemplation of re-using parts and for checking that you actually have the proper new part, and what you call all the pieces so you know what to ask for when you trash something and have to replace it.
It is of little value to the typical owner unless he wants to DIY an overhaul.
It is of inestimable value to the owner of an exotic car or other vehicle that is not locally supported, so that he can lend it to a mechanic he trusts and have some hope of getting back a usable vehicle in a reasonable time frame.
Mike Halloran
Pembroke Pines, FL, USA