I can't get the feeder tube off to clean the brushes.
To get at the brushes for cleaning, press the two locking tabs on the opposite sides of the tube to disassemble the feeder. There are two tabs at the top and two at the bottom.
The design of Pet Tutor® makes it easy to clean the hopper/feeder, brushes, electronic module on the feeder, the mount, and the remote.
The details on battery care, maintenance, and replacement may be found in the Pet Tutor® manual, section title Care And Cleaning [manual link].