A. This patch file are from the core devs.
B. You must replace the file with the patch file.
How to Backup an Installation and Upload the File:
1. Make a backup of your installation. Please refer the how-to backup using Softaculous here.
2. Download the patch file (1 file) to your PC core.zip
3. Extract the file if you want to upload via FTP client.
4. There are two ways to upload the file:
a. Login to cPanel, click on public_html/your_site/, upload the zipped patch file and extract. Refer to our how-to here or
b. Open your FTP Client, click on public_html/your_site/, upload the extracted file there.