It's pronounced roughly as "hoo gahn dit?"
Here are some other ways to say "how are you" in Afrikaans, depending on the situation:
* "Hoe is dit met jou?" (Formal)
* "Hoe lyk dit?" (Informal, often used with friends)
* "Hoe voel jy?" (How are you feeling?)
* "Wat is nuus?" (What's new?)