You reading the title of this article and yet continuing to read to the end of this sentence tells me that you've gotten a little tired of your comfort zone. It's understandable. Being one way for your whole life and dealing with people making (accurate) assumptions about you because of the way you've always been is getting tiresome and you just want to be someone else for a change.
You're completely in the right for thinking this way. I'm not saying that it's simple to get out of your comfort zone, but at least you're trying, and I guess that's all anyone can ask for, really.
Now on to the dilemma: you're tired of being you. Not in an "I'd rather be dead" way but rather in an "I want to have that super cool looking guy's life for like two hours and then I'm sure I'd be happy with mine" kind of way. The first step toward getting out of your shell is to do something scary. Not absolutely terrifying, just a little bit out of the norm.
For example, if you're an incredibly shy person, strike up a conversation with the person behind you in line at Starbucks. And would you look at that! You're taking up an entirely new way to start your day! If you're an incredibly outgoing person, try to listen to someone for a whole 10 minutes without having a response at the ready. Just listen. Maybe you'll find that that's all the change you needed! A little introspection goes a long way.
By doing some new scary thing every day, you'll find that you're kind of becoming a new person every day, building a new persona little by little. Here's where we run into a little bit of a hiccup in this seemingly easy plan. Now that you've started becoming a little more outgoing (I'm going with outgoing because I think that's the audience I'm speaking to here), people think that you're going to be into doing things that are downright terrifying, not the slight scariness that you've been used to.
I ask, though I know it will be terribly difficult after all this character development, to look at the person you were before it all. Believe it or not, deep down, they do still exist. You have to return to your core values and think, am I really doing this? Am I doing this because I want to or because I want to be someone else? How different from myself do I want to be? Is it worth it?
Once you run through those questions, you've hopefully decided whether you're doing something because of your newfound confidence or because of peer pressure. If it's confidence — good for you! If it's peer pressure, just back away. It's okay.
One day you'll be ready for the downright terrifying, but if it's too much, then don't sweat it. Sometimes we all think of becoming better and more courageous as a direct relationship, a solid line from the vertex up. It's really more of a scatter plot. You'll have good days and bad, returning somewhere where you thought you grew away from. That's okay, you have all the time in the world to grow into the person you've always wanted to be.