How Can I Edit Existing Templates?

You can change any of your custom templates. 

Under the Mailings area, navigate to the Templates tab. Choose the template you want to edit, make the changes you want and save it.

Please note that this will overwrite the previous version of the template. The older version can’t be restored. 

If you want to save both versions, follow these steps:

1) Create a new campaign and choose the template you want to edit

2) Edit the template and save this version as a new template from the Editor area.