If you have pointed the nameservers of your domain to Brilliant Directories (ns1.directorysecure.com and ns2.directorysecure.com), then all of the DNS Zone settings associated with your domain and its subdomains (A Records, CNAME records, TXT records, and SRV records) can be managed directly through your Brilliant Directories account.  To edit these settings, please follow the steps below:

Login to your cPanel account by going to Developers - cPanel Dashboard:

If you do not see this link in the Admin area of your site, please submit a ticket to request this access.

Once logged in to your cPanel account, click on "Zone Editor":

Here you can edit all of the DNS Zones associated with your domain.

Editing A Records / CNAME Records for a New Subdomain

Find all of the zone files associated with your new subdomain  (For more information about creating subdomains, please see this article).  For example, if you created a subdomain at blog.mywebsite.com, there will be several records that contain blog.mywebsite.com in them.  These may include things like 

For each of these records, do the following:
  1. Click on "Edit"
  2. Select "CNAME" or "A" in the "Type" dropdown, depending on which type of record you would like to change it to
  3. Enter IP address of the A Record in the "Address" field or the domain of the CNAME record in the "CNAME" field
  4. Click on the "Edit Record" button

Once the above steps are complete for all of the records associated with your subdomain, it has been pointed successfully!