See Power Off the Rack.
Press down on the strap connector's tab and pull to detach the strap from the side panel.
The locks are located on the bottom, center of the side panels.
Turn the two fasteners next to the panel lock clockwise. You can find the side panel removal tool in the shipping kit. There are 10 fasteners per side panel.
The left and right side panels are different, so note which side is the left and right panel.