BBQ 720-0266 Assembly & Operating Instructions page 10

STEP 7:
Secure head unit to cart with 4 (1/4" x 15mm) truss head screws & split lock washers as shown in diagram.
(Note: remove the cooking grids before this step)
STEP 8:
Attach side shelf with 4 truss head screws (1/4" x 10 mm) as shown on the figure below.