If you're asking "how is it?"
* Comment ça va? (Informal)
* Comment allez-vous? (Formal)
* Comment ça se passe? (More neutral)
If you're asking "how is it that...?"
* Comment se fait-il que...?
* Comment est-ce que...?
* Comment cela se fait-il que...? (More formal)
If you're talking about a process or action:
* Comment cela fonctionne? (How does it work?)
* Comment est-ce que ça se fait? (How is it done?)
* Comment cela se passe-t-il? (How does it happen?)
If you're referring to a specific thing:
* Comment c'est? (How is it?)
* Comment ça? (How is that?)
For example:
* "How it is going" could be translated as "Comment ça va?"
* "How it works" could be translated as "Comment cela fonctionne?"
* "How it happened" could be translated as "Comment cela se passe-t-il?"
It's important to consider the context of your sentence and the intended meaning to choose the most accurate translation.