Barton 90139 Owner's Manual And Safety Instructions page 4

Step 3. Attach assembled parts (part A,D,L&K) to short side panels
(part B) of assembled parts (part A,B,D,L&K) using long bolts
(part #2), washers (part #3) and allen key (part #4).
D
Step 4. Attach bottom panel (part C) to short side panels (part B)
of assembled parts (part A,B,D,L&K) using long bolts (part
#2), washers (part #3) and allen key (part #4).
D
# 3
# 2
#4
A
B
#4
A
B
C
4
# 2 X4
X4
#3
#2 #3
#2 X4
X4
#3