Open the back window; on some models it may be easier to access parts from the front.
Pull the left and right side of the frame vertical so that the crossbar snaps into place. On some models you will need to use the enclosed pins to secure the crossbar to the left and right sides of the frame. Slide the pins through the aligned holes on the crossbar and right and left sides of the trailer frame.
Slide wheels onto the axle one at a time until they lock into place. Some models require that you lock the wheels into place with clips. Line up the wheel base and the frame of the trailer so that the all the holes align. Slide the clips through the holes and secure. Do the same for the other wheel.
Attach the rear hand grip if your particular model came with one. Align the handlebar with the two pieces of exposed vertical frame. Slide the pins through the available holes.
Lay the trailer on its side. Slide the tow-bar onto the bracket, the bracket sticks out in front of the trailer about an inch. Use a pin to secure the tow-bar into place.
Attaching the Hitch
Use a wrench to remove the left side rear hub-nut.
Slide on the washer and the hitch.
Use a wrench to bolt on the rear hub-nut. The hitch should be vertical from the floor.