Turn the block over and line up the dowels in the block with the holes in the plate. Push down firmly and start the dowels into the holes with a side to side movement as you push down. With both dowels started approximately 1/8 inch into the holes, tap with a soft hammer until the block is all the way down on the plate.
The shoulder screws or tie screws may now be tightened. Remember that the idler gear shoulder screws are left hand. To be tightened, they will need to be rotated counterclockwise.