Replace the wiper roller at every printhead replacement.
The positions of the wiper rollers correspond with the positions of the printheads. Standing in front of the printer, position 0 is the outer left position and position 4 is the outer right position.
From this point you can also follow the video instruction. After that, proceed with step number 17.
Remove the complete protection foil.
Do not touch the micro-fibre surface of the wiper roller.