How to change emirates id mobile no??

According to the Federal Authority for Identity and Citizenship in the Emirates, the identity card holder must notify the relevant department of the authority of any change in the data included in the identity card within a month of the date of the change.
In order to make any amendments, or updates to the valid identity card, the concerned person must go to one of the Customer Happiness Centers, accompanied with his original passport and identity card and request the necessary amendment from it.
Note that the data modification service on the existing identity card is not available electronically, and this applies to identity cards issued to citizens and residents of the country.