First, to change money anywhere in Morocco, you will need to provide your passport. The exchange rate at the airports is not the best. It's common that at the airport, instead of cash they will give you a special temporary bank card. My advice, change some part of the cash at the airport and the rest in the city or use your bank card. There are many ATM's in all cities, and you will save a hustle carrying a lot of cash. And always check the change!