Right-click part01.rar and select "Extract Here" using a tool like WinRAR or 7-Zip . It will automatically pull data from all other parts.
The "2GB" in the name indicates each part of the download is 2GB in size. Installation Instructions DODITW3_2GB.part04.rar
Multi-part RAR archive. You must download all parts (e.g., part01, part02, etc.) and place them in the same folder to extract the contents. Right-click part01