You cant do much wrong, just install harrys addon on a fresh OSMC Image. If you dont like it you can easy choose another platform or roll back? Addons can be installed as "zips" from inside Kodi(OSMC). Thats about it, the rest is trying, trying trying... this is already as easy as it is. If you already have expierence with Home Theatre PCs and XBMC/KODI this is so easy to setup that a manuel for this is not really making sense. Only a list with stuff you have to plug in your USB slots. Maybe some GPIO wiring, that can be explained regarding Rear camera but thats about it.
Addons .: