I would in a heartbeat. I love my life, but that doesn't mean I wouldn't jump at the chance to do it over.
If I could go back in time I'd go back to a time when there was no electricity, no guns, and lots and lots of trees. And I would live out my days there in complete happiness.
Of course, you have to ask the question of, if I went back would I still have my memories? If you didn't, wouldn't you just make the same choices based upon the same circumstances that you did before? If you don't have your memories, aren't you just fulfilling fate, destiny, a pre-set plan?
How would you change it if you didn't know what to change?
Which is why I would choose to go back to a time where there was nothing that I could relate to, so that if I can't take my memories with me, I can at least escape repeating myself for all eternity.