Please contact us by Cloudocrsdk@abbyy.com and specify your current account and a new one in your request. Note that this new account should not be registered in ABBYY Online database. Kindly write the "E-mail change request" subject in your message.
Also it is recommended not to use private emails for this, so it is not bound to a person which may leave a company or move to another position. Having a dedicated corporate email for a person or a group of people is the best practice. With such email you can change notifications recipient and owner of the Cloud OCR SDK account without involving the ABBYY staff.