Toyota Prius C 2011 Owner's Manual page 73

1-4. Adjustable components (seats, mirrors, steering wheel)
■
Releasing the seat belt
Release the rear center seat belt only when necessary, such as when
folding down the rear seat. For safety, always store the plate in the
designated place after releasing it.
STEP 1
A
72
B
B
A
To release tab "A", press the
release button.
To release tab "B", insert the
mechanical key or tab "A" into
the hole on the buckle.
Retract the belt slowly when
releasing and stowing the seat
belt.