Johnny 5 base Assemble

Hi ,
I get the johnny 5 with the torso,but when i assembled and tested it ,then the torso dropt from the base ,why?
I assembled it according to step 2 from step 9.(Arm Base Assembly Guide v1.0.)
How to connect the base and the base top ?

If anyone could answer this question it would be very helpful! thanks a lot in advance

Here is the text for step 9. Pay close attention to the last sentence…

Unfortunately you will have to remove the servos in order to install the servo screw into the rotating top part. :frowning:

thank you very much !