While working with files in SharePoint especially the ones in the Style library or the master page gallery, it is always good to have a backup in case something goes terribly wrong. Fortunately it is not too difficult to create a backup of certain folders in your local. One would have to follow these steps-
- Load your SharePoint site.
- Click on the gear menu on the top right hand corner.
- Select Site Contents.
- On the ribbon at the top, click on the Library tab.
- Goto the Content and Export Group.
- And click Open with Explorer.
- Now you can quite easily drag and drop the folders you need.