Add or remove administrative users in Central Admin
Introduction
Additional users can be added to or removed from the Central Administration area
These users will be able to manage the onboarded end-customer tenants.
Add a user
To add an administrative user in the Central Admin Portal click the Users menu item.
Click the 
+ icon to create a new administrative user.
Type the Invitation email address.
If the user is to be able to invite other users enable the Is Tenant Administrator. This can be changed later.
The administrative user receives the invitation email and clicks the Accept invitation using the invited account.
Remove a user
To remove an administrative user in the Central Admin Portal, open the user and enable the Is Deactivated and then click Delete.
