⬢What is missing or is different in the MMU1 to MMU2S upgrade kit:
⬢The kit doesn't include all motors. To be exact for the MMU2S unit you need to have 2 motors, which we already have disassembled from the MMU1. (Note the third motor in the picture was used to build MK2.5S extruder)
⬢One disassembled motor will be used during the idler-body assembly. There is a note to remind you :)
⬢The other motor will be used as a "pulley motor" for the MMU2S unit and needs extra assembly, which is covered in the MMU2S assembly manual.