You can request a withdrawal via the Account Menu ; select Bank then Withdraw. Where we are unable to withdraw back to your Debit Card, funds will be returned to you via Wire Transfer to the name registered on your bet365 account.
However, winning too often will see your account with bet365 restricted. This is why bookmakers don't like professional gamblers who consistently win. It is bad for business, and bookmakers are out to make money, not lose them.