Download all parts rar to desired folder.
(unrar e part01.rar)
of course, you must enter the correct filename.
You will only need to unrar the part01.rar.
Unrar will extract and combine all parts and write completed file to your /download/folder/.
If there are broken parts, unrar will not save the combined file.
In that case add the -kb switch.
(unrar e -kb part01.rar)
I clean up the folder using