Join Date: Aug 2006
Location: MUC (home), DUS (office), XXX (customer)
Programs: LH, AB, SPG, CC, Sixt, EC
Posts: 6,332
DUS is one of the easiest airports I know.
6.05 am the plane lands
6.15 am off board
6.25 am through immigration and hand luggage customs
6.30 am through re-screening
6.35 am at gate (likely bus transfer to plane) for PRG
I wouldn't be worried at all, as long as on time. If delayed, LH will take care of you by either direct transfer to PRG plane, book on later flight or send you by the way of MUC/FRA to PRG.
Just don't waste time, but there is no need for emergency rush. It's DUS, it's a mini-HUB, it's Europe and not a crazy US airport connection.