To edit an existing template open the Channels tab, select the channel you want to edit in the Channels list and press the Edit Template button. You'll see then the Edit Template dialog box. See its description in Channel Template dialog.
Editing templates is usually necessary in the case when the Screensaver displays the wrong data from that channel or the message "Wrong data received" is displayed. If it happens with a template from the general Screensaver database, give us to know, please, to 
. We'll correct this template and refresh the database as quick as possible.