In cPanel & WHM version 90, we removed WHM’s Edit DNS Zone interface.
We replaced this interface with WHM’s DNS Zone Manager interface.
If you need to modify a record inside one of the DNS zonefiles, this is a method to accomplish it.
1. Log into WHM as 'root'.
2. Navigate to the following location: WHM: Home -> DNS Functions -> DNS Zone Manager
3. Location your domain, and click the 'Manage' Button
4. Find the 'record' you wish to modify.
Example: cptest-2.com (A) record
5. Click the 'Edit' button on the record you locate.
6. Modify the record in the manner you wish.