OPTION 3:Upload Via From FTP
If deleting a theme makes your nervous, or you have an issue when uploading the theme via the WordPress dashboard, you can upload it manually by FTP.
1. Re download the theme files on ThemeForest (ThemeForest always have the latest version of the theme). So login to your Envato account, then go to Downloads, and download "Install able WordPress file Only" package.
2. Unzip the Jewelar.zip file on your computer
3. Rename the root folder to something like "themename-new".
4. By using an FTP software (such as FileZilla), connect to your FTP.
5. Upload the folder to .../wp-content/themes/ (so you should have /wp-content/themes/themename-new/)
6. Once everything has been uploaded, go to WP-Admin > Appearance > Themes and activate your new theme.
7. Make sure to reactivate the plugins by going to WP-Admin > Plugins. If one of your plugins has not been updated (ex: Visual Composer), go to WP-Admin > Plugins and delete the old plugin.
8. Go to WP-Admin > Appearance > Install Plugins and reinstall the plugins. Make sure to "activate" them again.