Point to itunes library

The external hard-drive that I used for itunes crashed. I have a back-up of my itunes library, song files, etc on another external harddrive, but I cannot get itunes to recognize that library. I have tried changing the location in preferences. There is nothing in the current library to "consolidate", so that doesn't work either. I started itunes with the new harddrive attached.

I knew enough to make a back-up of my music, but don't know how to use it! I would appreciate help on what to do in order to use my back-up harddrive. Thank you!