vz61 scorpion repair part help

[ryo]

i have a vz61 scorpion that im trying to repair the gearbox broke on it and i got a replacement but i carnt figure out where one part that fell off goes

http://www.actionsportgames.com/files/asg/...orpion_VZ61.pdf

the part is v- 16 on the diogram but i carnt see how it connects

anyone else tryed to repair one before