Koshering a coffee machine

I received a coffee machine from someone who does not keep the commandments. There is a part there where you add the milk, and I am worried that they used non-kosher milk in it. What can I do?

Dear …!
In Israel, non-kosher milk is extremely rare and one does not need to worry about it. However, if one uses powdered milk, that sometimes contains milk from an unsupervised non-kosher source.
If the device requires koshering, there must be a way for the water at a temperature of 100 degrees Celsius to reach all the pipes.