The PnP head is somewhat complex assembly. You might want to have a peek at step 13, where there are pictures of the completed head assembly. You can also download a zoomable and rotateable PDF of it.
The head design has been upgraded from the first version. These instructions are for the current version (shipped after Sept. 28, 2016). There are links and notes to the previous version where appropriate.
Attach one of the bearings* (5) to the PnP head middle plate (1) with M3-8 bolts (2), M3 washers (3) and M3 nuts (4). Tighten these.
- PnP head middle plate
- M3-8 x 2
- M3 washer x 2
- M3 nut x 2
- JFRA8 bearing* x 1
*: Current type is JFRA8, old version was LHFC8.