Lexmark 4I3 - Manual (Page 114)

2. Grasp the lower section of the F3 paper door with both hands.
Then align the grooves at the top of the door with the hinge pins
on each side of the printer. Be sure that you align the door at
the angle shown. Then slowly push the door in place.
F3
P a p e r D o o r
Ta b
S lo t
H in g e P in
The F3 paper door locks in the open position similar to the
standard door.
1-92 User’s Guide