It’s very easy.
Before the first use, just sterilize by immersing the pacifier in boiling water for five minutes.
Afterwards, just clean on a daily basis, by washing it in mild liquid soap under cold running water — if it needs an extra thorough clean place it in a strainer and sterilize it by pouring boiling water over it. But don’t boil it again and never leave it to cool down in boiling water.
It is not dishwasher-safe. And we don’t recommend the use of sterilizers.