eBay templates live in the Description Field of eBay listings. If you want to remove the template from your listing, you will need to do so without removing the actual description of the listing. So simply deleting the entire field is not a great solution. However, Listing Mirror provides one.

You can create an advanced template that has only {{ description }} in it. What this will do, is remove whatever template was there before and populate the Description Field of the listing with the description from the master listing and nothing else. 

Template Removal Steps 

1. Delete your current template. 

2. Create an advanced template and insert the following characters, exactly:  {{ description }}

3. Apply template to your listings by using the Listings Edit template in Bulk Edit Templates and assigning the Template ID in the template fields, or by editing the template field in the listing directly.

The change should happen quite quickly, depending on how many eBay listings you have. You can always test a SKU first, by choosing the new template in the Edit Listing page, just to make sure you have done it correctly.