Move the wooden front cover plate to gain access to the two filter mats. Ideally, throw the old filter mats immediately into an almost full rubbish bag and dispose of it immediately in a skip or keep it on the balcony until it is collected. After replacing the filter, close the front flap and enjoy the best air quality.
Caution:
The used filter is full of allergens. Disposing of it quickly is the top priority.
Please do not attempt to clean the filter mats with a hoover. The filter mats have a higher degree of separation than your hoover. This would lead to a dramatic increase in suspended particles in your room.