installing serpentine belt on 1997 Mercedes-Benz C230

First time replacement at 70k miles. Owned car for 2 years, bought at 30k miles. I replaced the water pump 1 day ago (Monday). Removed belt with no problem and no tensioner? just slipped off ok.
BUT trying to put it back on is a no go.
How does it get back onto the pulleys? Do I need a special tool? Do I need to monkey with a tensioner. Is the tensioner the smooth idler on the top right of the engine? What gives??? Thanks

Asked by for the 1997 Mercedes-Benz C230
2 answers , please help I need to put the poly v belt back onto c-230 20062006
I am considering the purchase of a 97 c230 with 81000 miles. Would you?
I am a graduate student and trying to us my money properly. Don't want to by a nightmare. Please offer opinion.