Should I change my iphone 5c to 5s?

Well I got white iphone 5c and I wondering I should change it to a 5s?

Well, you should if you could afford to. The Iphone 5s is a 64 bit phone, meaning the phone would run faster, much faster. The ios 7 is supposedly be design for the 5s, meaning if that is true, we can expect to see lag in non 64 bit phone. Also, app is going to come out that can run only with 64 bit. All in all, if could yes, if you can't wait and get a future iphone or when the price drop somewhat. Of course, there's a option to switch to other phone, but iphones are nice.

Only you can decide that.

Can you afford to do it? Do you need to do it? Why do you really want to upgrade? What are the features and benefits of the 5S that you need that do not exist on the 5C?

Ask yourself these questions and they will help you make a decision.

In repsone to @Kevi's answer there's no discernible lag on an Iphone 5 versus 5S with Ios 7.

No unless you really want a new phone and show it off. Other then that just know that apple is constantly changing and making new models every year so I would wait for the new Iphone 6 which I'm sure is going to happen and will be the best yet! And if you can afford it and think its worth changing the iphone 5c to the new iphone 5S then buy it.

How do you just "change it"?

Yes, if you have the correct payment.