Briggs and Riley : Wheeled Expandable Uprights

The Expansion Devices are easy to use.
1)  There are 2 pull-up devices inside.  They are on opposite sides of each other.
2)  It is easiest if you use both hands when trying to expand side out for more room. 
3)  Use the  lower hand for leverage, while the other hand pushes the button and slides the side up.