This is only a warning of the complexities of the Shimano roller brake R-im80 bicycle brake system used in the rear wheel some Apollo vintage style Woman's commuter bikes.
The key to fixing everything is in the skill of reassembly specially the Shimano roller brake system. Disassembly with out experience of reassembly is potential repair failure with this brake system. In a scale of 10 difficulty is close to 10 we can get due to the complexity of the Shimano system making this bake extremely hard for back yard novus to get to run smoothly again.
The roller brake is really a design suitable for the manufacture assembly line workers or theses who have reassembled this brake system hundreds and thousands of times before.
Before even touching one, it is important to understand once dissembled without the essential reassembly knowledge and skill the potential of never getting it working again is high.
An excellent youtube video shows how to do this. Type in your browser search field bar replacing brake pads Shimano roller brake R-im80.
When the results found page displays clicking on the video starts the video instructions.
At the time of writing, although the best instruction there is, there is no English version immediately apparent. Never the less, it is a highly recommended to skip the disassembly procedure and concentrate studying the assembly procedure first. Paying close attention, you will learn there is a right and wrong way to reassemble this system  before you taking it apart.
Reassembly of this brake system requires intermit familiarity with the video's reassembly procedure equal to the designer and assembly production line experience. So take your time going over it several times to equal with them. Reassembly is made a lot easer when you are familiar with the video's reassembly procedure before you start disassembly.