Just read these instructions and follow them carefully:
1. Download WinRar (or if you are a Mac user, try UnRarX).
2. Install the program
3. Download all "parts" of the file above (parts 1-3), make sure they are being downloaded into the same folder.
4. Choose to open part 1 in WinRar/UnRarx
5. Instruct the program to extract the file into the location of your choice on your computer.
6. The extracted folder should have all the files you need. The programs take the "parts" and put them together, there is no need to extract the other files you downloaded as they are already combined in the final extracted folder.