First, remove the screws circled in red:

Next, very carefully separate the housing. The components are loose inside the housing, so ensure the blue part of the housing is facing up when you separate them. Refer to the image below for how to put everything back if something falls out.

It is a good idea to remove each item individually and inspect it. Remove any debris from the housing and make sure the drive gears are clean. It is also a good idea to feed a piece of material through the material present switch (pictured below) to ensure nothing is stuck in it causing an issue. If you have canned air, carefully blow everything out. Then reassemble.