yeah good luck with that... it would be very hard to find a friends episode that doesn't require you to pay or file share. the best way i would suggest would be through torrent downloads. just go onto google and type friends torrents. you should find an endless list. you will need to download a program called tunebite or any other program that does the same thing to download these torents.
you know , i just start downloading it with tourent and that is just good , and has every season and every episode , by site downloading you may let them slip off your hands