If so, who? This question requires you to answer a couple other questions first.
First: Am I happy or unhappy with my life as it is?
This is a tough question to answer. It immediately makes me think of other questions that help me evaluate the answer to this one: Have I met or exceeded goals I have set for myself? Have I surrounded myself with people I love that support me? Am I fulfilled? Am I satisfied? These questions require some deep soul-searching, because it is easy to confuse temporary setbacks with not achieving long-term happiness. It is easy for us to get so wrapped up in the moment that we lose sight of the big picture. And in so doing we might be tempted to answer these big questions about ourselves in the negative, when upon deeper reflection we would reach a more positive conclusion.
Second: Is there anyone else who has a life that seems better enough than my own that I would trade with them?
That is what makes this ponderence different than asking how would you change your life? Every person's life is imperfect in some way. Everyone has their own set of challenges. It is easy to focus on one aspect of another person's life as being better than our own, but when taken in total, is another person's life better actually better then our own? When considering the complexities of people's lives, that is a difficult question to answer. You might even say that it is unanswerable.
My answer to the first question changes from day-to-day, hour-to-hour, minute-to-minute. Happiness is a nebulous concept and I roll in and out of it all the time. Ditto satisfaction, confidence, feeling loved and supported. But if I look at the big picture, I generally think that I am a pretty happy person. I have built a life for myself that, at least, allows me the opportunity to feel happy, satisfied, confident, and loved. I consider myself to be extremely lucky in that regard and am very grateful for the luck and opportunities that I have had, and may have in the future.
Presumably, by answering the first question in the positive, I would be ruling out answering the second question that way. However, I do have days where I want to get out of my own skin or experience things from someone else's point of view. There are people whom I admire, people that I think are more organized and disciplined than myself, and on some days I might want to trade with them just for the order and clarity that might bring. But the slippery slope of this question is that it is an all or nothing proposition, so I can't just take the traits that I want from someone else and keep the things I like about myself. So, I have to wonder, would I be satisfied with these other people's lives, in total? That is harder to say. The grass is always greener and all that. I'm inclined to believe in the end I would end up being unsatisfied with some other aspect of these people's lives. Choosing someone to trade with would be like buying a lottery ticket, where my best chances were to break even, or even be worse off, with only the vaguest hint of a chance that I would come out on the other end happier than I am now.
So, I guess I would trade lives with someone else, but only in a Freaky Friday sort of way, where it is temporary and I eventually get to be myself again.