Here's a breakdown:
* D as in "day"
* neh as in "net"
* proh as in "pro"
* peh as in "pet"
* trovsk as in "trovsk"
Note: It's worth mentioning that the city has been renamed Dnipro in 2016. So, while the pronunciation of Dnepropetrovsk is still relevant for historical purposes, it's more common to use the pronunciation of D-nee-proh for the city now.