I've tried to unpack the files with 2 different unrar programs and each failed, one with a CRC error and the other saying the structure was damaged. I downloaded the files a second time and had the same error when I tried to unpack them.
Just a thought...did you download all three files? It will not unpack if you only download partial.
I use Free RAR extract frog without a problem. I checked the pattern and there have been over 15 downloads so it must be working for some. Good luck!
When you click on the rar and it opens, try testing (or someting like that, mine is in Dutch), maybe it gives you a solution. If not, try it again. I had it a few times, but after 3 or 4 times download it worked.