How to Replace the Extruder Gears on a Bambu Lab X1C, P1P or P1S

If the filament reaches the extruder then keeps retracting, worn or gunked-up gears are a likely cause. Here’s the 20-minute swap on the X1C and P1 series.
How to Fix a Jammed Bambu Lab AMS 2 Pro

When pulling the spool out doesn’t clear it, the jam is deep inside. How to open the AMS 2 Pro, clear the motor block and reassemble it without losing a screw.