The manual is a little bit frustrated because of no detail as it should be, like 'part number'. 'Bolt & Nut' are pack in mix, so need to be compare to 'size' paper (which is separate pack might be better).
When install the structure part, consider the deep pierce face outside (because the bolt's head need to get inside to hide from the surface, which mostly have other part to cover it, so when it's in position, tighten as tight as you can)
The Z-rail tighten with balling arm before install it to the motor might help you install these parts easier.
Also, 'Mainboard & Power supply' installation are very frustrated. (Why you need to install it that way, very difficult to maintenance.)
But anyway, i still manage to finish it. :P
I call it 'semi' because you have to set Z-offset with distant as A4 thickness manually.
Very confuse with the result number from 'auto bed leveling' because no manual describe but i figure it out lately.
As the perfect line as '0', the '+' mean more closer to the print head (V) and '-' mean more far from print head and the acceptable length is +_ 0.8
so, if too much '+', level down the bed. if too much '-', level up the bed.
At this point, WOW! never a single fail print. !