For a simple stroller, the cloth seat can be easily removed from the frame.
As shown in the picture, the cloth seat has 2 long holes on its sides. To put the stroller together, people will slide the 2 holes onto the 2 sticks of the frame.
Would you say "to take the cloth seat off or out of the frame"?
I think it would be "off" because we put the seat "on" the frame.