Here's a breakdown:
* i as in "it"
* DU as in "duke"
* mee as in "me"
* uh as in "about"
However, there are other possible pronunciations depending on your background and personal preference:
* i-DU-mee-ah with a stronger emphasis on the final "ah" sound
* i-DU-mee-ay with an emphasis on the final "ay" sound
Ultimately, there's no single "right" pronunciation, and the best way to learn is to listen to how others say it or consult a dictionary.