Mainstays 4055019W Manual De Instrucciones página 20

Step 14
Y
14.1 Insert O into slots to the innermost, so
you can lever it for the other end;
O
O
O
14.2 When both ends of O are in place,
14.1
14.2 14.3
snap it down to the slot;
14.3 Lock O in place with Y as shown.
20