(I like a lot of things about Apple but their lack of interest in documenting hardware is one of this things I don’t. It’s ironic given that without Burrell Smith and his doc there would have been no Macintosh).
They have their hardware repair documentation online as part of their self service repair program, although I don't think they have finished adding all their products to the program.
> Read the repair manual for your iPhone, Mac laptop, Mac desktop or Apple display model to familiarize yourself with the steps required and the parts, tools, and materials needed for your model and repair type.