Simply sign up to transferwise:
http://transferwise.com/u/f0bdOpen bitstamp
Click SEPA deposit on bitstamp page to get payment/banking information
Back to transferwise and input the details from bitstamp by pressing the "make a payment"
Upload your funds to transferwise by debit card or bank transfer and when they get that payment, the will then send it on to bitstamp as a SEPA payment.
24-72 hours later your bitstamp account should be credited and ready to buy bitcoin