Do you have a question about the GBC 4250 and is the answer not in the manual?
Immediately stop the laminator and set the speed control to slow to begin clearing a film jam.
Depress the reverse switch and pull film from the rear until it unwinds completely from the rollers.
Release the reverse switch and run the laminator forward until all wrinkled film exits the rear.
If film is wrapped, remove the top film roll and pull film towards the front while engaging the reverse switch.