In order to do this first you need to download FireFTP by clicking you will be directed to the download page and add to firefox
What is FireFtp is a free, secure, cross-platform FTP client for Mozilla Firefox which provides easy and intuitive access to FTP servers. Features : Character Set Support: UTF8 and just about any other character encoding supported, Advanced properties (CHMOD, recursive CHMOD, thumbnails) Tutorials and help files available for support.
Launch FireFTP by selecting Tools -> FireFTP. It will open in a new Firefox tab. To add an FTP site to FireFTP, select the Create an account drop-down. You will be prompted with a “Account manager” window, enter your login details and click Ok. To connect to the site you just added to FireFTP, click the Connect button. To upload a file > right click the file and select Upload, to Download a file >? right click the file and select Download.
Tutorials on How to use FTP within Firefox Browser
