Carrier Board
Fasten the offsets of step 28 through the top plate into their respective offsets of the bottom plate.
Afterwards, install the carrier board using the fasteners of step 29 as well as the offsets included with the carrier board.
Carrier Board Assembly
The currently described order of installation requires partial disassembly of the carrier board.
An alternative method is for the original set of 12 offsets - currently installed into the bottom plate - to be installed into the carrier board through the top plate first, instead of into the bottom plate first.