It is probably the same process as for making "Greek" yogurt out of ordinary yogurt or preparing ricotta for Gnudi, or faking Labneh out of goat yogurt:
- you put a cheese cloth in a strainer
- you put yogurt / ricotta / fresh cheese in that cheese cloth
- you put it in a fridge, with a bowl underneath, for few hours / overnight for liquid to strain (trickle away?)

You can speed the process by using paper towls, it will work for ricotta or fresh cheese, but not yogurt, as it is too liquid.



btw, my dear English speaker: what is the difference between strainer, sieve and colander and do you drain or strain food in strainer?