This is a test of commonsense. Complete the next sentence:

How to clean a biometric scanner
Disconnect the unit from the power source
Keep a soft cloth handy when you are about to start cleaning the scanning area.
Take care while lifting up and removing the front layer of the scanning area.
Remove the part where the finger is placed for scanning.
Clean the area using a soft piece of cloth. If there are bigger dirt particles, try removing them using a light blower.