Place the middle shelf on top of the four spacers.
Now the tricky part is to place the top of the revolving bookcase on next. It helps to have anther set of hand, however, on person can put the top on by themselves. Lay the bookcase on it side and adding the top and bottom to something straight, such as a table or workbench.
It may also help to place a bar clamp on the top and bottom while you are working. Now center the self with the side support screw holes
