Please call us
Contact the design via private message, and let him or her know that you would like to make some modifications. Please keep in mind that the contract entitled you to the logo as is, and the designer has the right to charge you for additional changes. Most designers will be probably be willing to make basic changes free of charge though. For more sophisticated changes you should expect a charge for the extra charge. If you have paid in advance, you will have to negotiated prices and payment with the designer directly.