Is it possible to replace the home button and the lock screen button on a iPhone?

I've had my iPhone for about 2 months now, and the buttons are starting not to work. Besides the buttons my iPhone is in perfect condition. My phone carrier is straight talk, from Walmart. They don't offer insurance or a warranty or anything like that. So I was wondering if it was possible to replace these buttons?

Since your iPhone is only two months old, why don't you drop into an Apple store and see what they say as your iPhone warranty is still valid.