just download all pieces to the same folder and extract from part1.rar as if it were the only file (rar will know what to do -- you don't need to extract from part2..3..4.. ever; only part1). Do this for sf3_ryu and ryu_snd.
Finally take the sf3_ryu.snd file from the ryu_snd.rar and add it to the sf3_ryu directory. As for the patch, its up to you if you want to use it. Personally? I like to install the original as I described above and then make a copy of the sf3_ryu folder (call it sf3_ryu2) and then add the contents of the patch.rar to this and copy over the files. This way you can see the difference between the patch and unpatched versions and decide if you want one or the other, or both.