Generally speaking, a swivel chair will normally have a FA (Fully Assembled) base for ease of assembly.
Occasionally however, in order to sell the product at a better price by getting better shippig rates on smaller box sizes, we need to use a KD (Knock Down) base.
This does lead to a more complicated assembly as the swivel mechanism needs to be accessed from inside the base and assembled onto the underside of the chair, requiring access to the interior of the cavity.
See the video below for how this needs to happen.
The key element here is that the bolt holes in the chair base are lined up with the assembly holes of the swivel mechanism you’re installing. Customers may need to swivel the mechanism itself to get access to the bolt holes. Everything else is simple after that.