If this is bissel 7920 then there are 6 screws that can be accessed from top of the base. 2 in the front, 2 in the middle after taking out the water container, and 2 at the back.
It comes apart quite easy after shaking it a few times Be warned getting it back together is no easy task and an element of luck was involved before it decided to suddely click into place.
bigjohnl1951
January 2007