How to manage DNS zones in WHM?

WHM contains a number of tools that allow you to manage your zone files. They're in the DNS Functions category of the menu
1) Let's start by adding a new DNS Zone
2) Enter an IP address to use for the domain name
3) Then, enter the Domain Name itself
4) Finish by choosing which account should own the new domain name. You can also assign the domain to the system, if it shouldn't belong to any user
5) Click Add Zone to save
The new DNS zone has been created successfully using the standard zone template
Let's edit the zone
6) Select it from the list.
7) Hit the Edit button.
Since this page is fairly large, let's open this frame in a full-sized window for the sake of this demonstration
You shouldn't need to edit anything in this first section of text fields, except for the Serial Number. This number lets DNS resolvers know when this record has changed.
8) Now that you've learned all about the different kinds of records, let's add a few. We'll add two nameserver hosts
9) This number represents the record's Time To Live -- TTL, for short. It tells a DNS resolver when to check our nameserver for updates
10) Specify a TTL in seconds. The default is 14400, or four hours, but we've changed our default to half that value
Remember -- hosts should be A records
11) Finish by entering an IP for this record
12) Now, repeat for a second nameserver host
13) Click this checkbox if you want the local mailserver to accept mail for this domain even if the primary MX record you indicated does not point to this server
14) When finished here, click Save.
That's it! The zone file has been modified. Now, let's delete the zone
15) Use the Delete a DNS Zone tool
16) Select the zone from the list. Note that you can select multiple zones, if you wish
17) Click Delete
18) Confirm the deletion
The zone has we created has now been removed from the server
19) WHM provides you with another way to edit a zone's MX records. Click Edit MX Entry
20) Choose a domain to edit
21) Click Edit
22) Enter a destination mailserver, changing the priority if you wish
23) You can add another MX entry field with this link
24) Or, Delete a field as such
25) When finished, click Save
The domain's zone file has been updated to reflect the changed MX records
This is the end of the tutorial. You now know how to manage DNS Zones in WHM