Goto "Your Account > Cashout". What you see there depends on if you have the 15 euros or not.
Only when you have reached that magic figure will you see the payout details. I use Paypal, so I just have to enter my paypal email address. There is probably another choice of payment processor - like Payza or whatever name it uses now!
Then you wait! Despite what you may see in this forum, most payments are made on time. Less than 30 days and often within 10 days.