Your frien needs to ask his Spanish bank for a SWIFT payment. He will need the IBAN for his English account and also the BIC for his UK bank (this information is usually found on his statement).
There will be a minimal charge for transferring the funds, and he can send the funds either in Euro, or ask his Spanish bank to covert them to GBP before making the payment. If the funds are sent in Euro and he wants to credit his GBP account, then his UK Bank will convert them upon receipt.