You can edit or remove MX Record from cpanel using the cpanel DNS Zone Editor which allows you to manage, remove or modify DNS records.
1. Log into your cpanel account. (eg: www.example.com/cpanel )
2. In the "Domains" section, "Zone Editor" Icon.
Under "Domains", you can see many options below the "Actions" text.
3. Click on "Manage" and the DNS records will be loaded on page.
edit or remove. Should edit a MX record, click the "Edit" option, modify the details and then click on "close Record". Removing a record can be done with the "Delete" option.
Note: It may take anywhere from 12 to 24 hours for the changes to take effect worldwide.