IBM 3 User Manual page 212

202
4247 Model 003 User's Guide
thumbs (1) until the tractor locks in the fully extended position (2).
Continue with step 5 on page 203.
d. Open the front tractor cover to its locked position.
e. Grip both sides of the round tractor shaft while operating the tractor
release levers as shown. Lift the tractor out of the printer and set it aside.