Don't you mean FileZilla? Or FireFTP? If it's FileZilla, just type in the domain name (no www) on the "Address" input, then type in your username (usually you@yourdomain .com but without the space between yourdomain and .com - and the you@yourdomain is obviously an example placeholder) and then the password. Once you've logged in, just go to your Web folder (most cases that's public_html but it can be www or even web) and then drag the file from the left panel to the right panel. It'll upload from there. One thing I like to do is save the login info in the Site Manager - that way I don't have to remember the account information. Of course, I keep the informaiton handy for just in case, but it is very convenient.
http://www.thesitewizard.com/gettingstarted/howtoupload.shtml hope this helps. [assuming it is filezilla ]