No problem.
That Filezilla programme will only do ftp transfers, so firstly, you'll need a different client programme. There is an extensive list of the more widely known clients here:
BitTorrent client - Wikipedia, the free encyclopedia
and this section:
BitTorrent (protocol) - Wikipedia, the free encyclopedia
gives you a basic idea of what it does.
Personally, I use UTorrent on M$. Seems the most configurable with the least phaff that I've found upto just.
Torrent - The Lightweight and Efficient BitTorrent Client
In a nutshell, download and install that programme, (or fire up your existing torrent client if you have one installed), then click upon that little green torrent icon on the downloads site. You will then be prompted to open or save the torrent file. (A small file which just contains the info required to download the actual main file itself). If your torrent client has been set as the default to open .torrent files, click on open and your torrent client will take over from there, (prompting for any options it may require), or click save and it will ask for a location to which to save the .torrent file. Save the file to wherever you normally would for something you download. Then, open your torrent client and tell it you wish to add a new torrent. Point it to the location of the .torrent file you just downloaded and then it will, (again, if required), prompt you for any options it may require before adding the torrent.
After adding the torrent, just leave the client to do its work.

You may find that it takes several minutes to find any available seeders. That's nothing unusual, so no need to worry if it does.
What will happen using this system over the ftp method is that your torrent client will connect both to the seeder running on the server and to anyone elses machine which is in the process of downloading or seeding that same file as you are downloading. What then happens is that you literally share the file between yourselves, as well as getting missing parts of the file from the server. The server seeder is there to make sure that a seed for each file is always available. The more people who are downloading or seeding that particular file, however, the faster your download should become, as you will be getting parts of the file from several different machines.
At a push, if you can't get to grips with the torrent system, a couple of ftp connections have been left in place as a secondary download system, so the ftp option is still available, (when it has a free slot). You should find that the torrent system performs better, however, especially if there are other seeders/downloaders for that file.

That's why I've put this system in place in preference of the ftp system. I used to get no end of grief about the ftp server being busy and having no available download slots, but with this system, it isn't as dependant upon the server itself for the data transfer, so the availability should, theoretically, be better, especially as more people leave their machines seeding the file(s).
The server is still completely in control of tracking and the initial seeding, (just to allay anyones concerns),

but the distribution system should improve the file availability notably eventually, (one hopes).
Once a download is completed via the torrent system, btw, it would be greatly appreciated if you could seed the file(s) you've downloaded for a while from your machine. That way, it will give anyone else downloading the same files the benefit too.
