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[jaikrishna.t]

Download your desired theme from here (you can also get from developer if it is premium/paid).
Connect to your account via FTP. Guide for reference:

How to upload files with FTP

The best and most reliable way to upload files is to use FTP. To upload files with FTP, you will need to following: Your FTP username Your FTP password The FTP hostname An FTP client You can find your FTP username, password and hostname in the client area under the FTP Details section. The FTP password is the same as your hosting account and control panel password, which is different from the password for the client area. If you like videos better then text guides, you can find one at the bot…

Hover over to htdocs/wp-content/themes.
Extract your download .zip theme file.
Upload the extracted files to the server.

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