FTP (File Transfer Protocol) is a method by which you can transfer files between computers, usually using the Internet. When using FTP you use an application called a "client" to connect to a machine called a "server". We recommend you download FileZilla (http://filezilla-project.org/download.php
cPanel allows you to setup FTP accounts so that certain external users can access a restricted part of your system. You can also set up an anonymous FTP account so that anyone can access a restricted part of your system. You can also manage these FTP sessions, cutting them off if they go on for too long.
Warning: FTP, by its very nature, allows external users to modify your web site (albeit a restricted area of your web site). External users can upload, download, and delete files. Keep this in mind when you set up an FTP account for third-party user.
Your FTP web server: ftp.yourdomain.com
Your FTP username: email@example.com
FTP password: yourmainpassword
Once you log in to the FTP, you will see some set of folders. Open up the "public_html" folder and upload all your website files into it.
*Note: Do not delete any other folder/subdirectory etc already lying there.