you need to open them using winrar and there should be a image file inside. Then you burn it using a program like 120%.
1.download and install winrar 2.right click the first winrar file in the group some like .001 or .rar01 3.click extract here and it will extract 4.open up 120 and burn that image file....
WINRAR is what you need to extract the file. Then burn it with nero should be fine. I would recommend dvd decrypter if its an .iso or alcohol 120% if you have that available.