When you no longer need documents, pictures, other files in a library, you can quickly delete them. Just be careful and make sure that no one else needs them either. Deleting files may be permanent and you may be unable to recover them. If you think that you might need the files later, consider moving the files to another location instead.
Make sure the files that you want to delete are not checked out by refreshing the browser and noting the icon in the Type column. Files must be checked back in by the person who checked them out before you can delete them.
Select each file that you want to delete by hovering over the file and then clicking the check box.
In the header, click Files > Delete Document.
If you delete files by mistake, you may be able to restore your files to the site, depending on how your site was set up.