This aspect is a bit over-rated as to detail. The amount of thermal paste the Apple factories applies to the processor surfaces is huge, spilling onto the green surfaces of the processors. This can be seen once one removes the heat sink component that sits on the processors. Gobs and gobs of thermal paste abounds everywhere.

As the pic in step 22 reveals, the Apple factories in Asia apply a huge amount of thermal heat sink paste goop to the top surface of the processors. The need for a special primer on this reapplication procedure (other than the removal and cleaning of the old paste from the processors' surfaces) is over-rated.