You can edit/modify/delete an email account using cPanel; you need to navigate to the cPanel 'Email Accounts' page, and this page provides the functionality to manage the email account(s).
Hosting Account->Manage->cPanel(quick links)->Mail->Email Accounts.
Manage page (then click cPanel, within the Quick Links section)
cPanel page (then click Email Accounts icon, within the Mail section)
Click this link to view a video demonstrating how to manage email accounts.