Thanks for this.
The black circular spacers shown at step 6 go on the mounting brackets for the two outermost screws holding the screen onto the mainboard. On the first picture for step 5, if you numbered the circled screws from left to right, those would be screws 1 and 4.
I didn’t have a screwdriver for the clutch screws of the back cover, but a thin, pointed knife tip did the job.