How to Edit Email template in Salesforce classic?

Hi,

Editing options vary depending on the template type.

• For text templates, click Edit to change the message content, subject, or merge fields.
• For custom and HTML templates:
  • Change the content or merge fields of the HTML version by clicking Edit HTML Version
  • Change the content or merge fields of the text-only version by clicking Edit Text Version
• For Visualforce templates:
  • Change the markup of the template page by clicking Edit Template.
  • The Visualforce Attachments related list indicates which attachments are being generated through Visualforce markup.
  • If the Visualforce markup references components in installed managed packages, the Version Settings related list shows the package versions of the installed packages containing the components. Some kinds of components in installed managed packages can include another class, a trigger, or a custom object.
  • If the email template includes encrypted data, remember that the data is displayed as encrypted within the generated email and in the Visualforce template page. For security reasons, it isn’t displayed in plain text.