Please simply download the latest version of theme/plugin from your profile and re-install it.
You can overwrite the theme folder via FTP. Please note that before updating the latest version, please mark and copy all files that you have edited or customized, then update. After finishing, you add all codes that you customized to your new theme. This way you will not loose all the customization. Also please take back-up of your site.
Let me know if you have any difficulty.
Please login or Register to submit your answer