Changed Rating on Podcast iTunes....how change back?

I just inadvertently undid all the ratings I had given previous podcasts, going back a couple of years on iTunes. I haven't synched the iPod since then, so the old ratings are still on the iPod. Is there anyway I can just "go back" on the library file on my Mac so my stupid move can be undone??????

How about if I turn off iTunes, rename the old iTunes Library files to "old".......and then sync? Will iTunes re-create the library as it was before?????

OK......new question......thankfully I found out that I had backed up 2 days ago, so I'm good on the library question.

Now.................some of my podcasts have a star rating already set, which means every new podcast is automatically set to have say 3 stars. Not good! Soooooooooo, how do I change that? I don't remember setting it, but wanting to change it to "none" is what got me in this pickle to begin with.