VTech Go! Go! Smart Wheels 4-in-1 Zig-Zag Raceway Instruction Manual page 12

Once you've completed the above steps, the Zig-Zag Track ready to play!
Stunt Raceway
1. Disassemble J, K, G, H and I. Slide G into the second floor.
2. Insert I into J, then slide J onto the first floor slot.
12