A simple guide to help you remove a subdomain in cPanel.
Step 1: Log into your cPanel account.
Step 2: In the Domains section, click on the Subdomains Icon.
Step 3: Under the Modify a Subdomain list you can see a list of subdomains.
Step 4: Click the Remove option under the Actions tab.
Step 5: You will receive a warning that you are removing a subdomain.example.com. You will need to click on the Delete Subdomain button to remove your subdomain permanently.