How do you say how to bb in french?

There's no direct translation for "how to bb" in French. To understand what you mean, I need more context. "Bb" could refer to:

* BB cream: In this case, you'd say "Comment appliquer une BB crème" (How to apply BB cream).

* "Baby" or "bebe": In this case, you'd say "Comment s'occuper d'un bébé" (How to take care of a baby).

* An online abbreviation: In this case, you need to provide more information about what "bb" stands for in the context you're referring to.

Please give me more context so I can help you translate "how to bb" accurately.