Twenty Eleven Template Come Back!

How do I get a hold of another Twenty Eleven template code? I was dumb and changed the code. Mostly I just commented out most of it, but I also added some code. I was told that I should create a child template, but I would like to have the twenty eleven template back. is there a way to do that?

Thank you! Any help is much appreciated! I am new to this, but I learn quickly, so your efforts are not for nothing!

Jennifer