When you click on View Campaign List (PC762) in Campaign (PC760) at Telgoo5 left panel, a screen will be displayed with all created Email and SMS template.

If you wish to edit any template, you have to click on the Edit icon for a particular template. See below image.

Once you click on the edit icon for a template, a popup window will be displayed. 

After changing in the existing content, you will get success message by clicking on the update button.