How to get my iPhone 5 screen replaced by Apple?

I cracked my iPhone 5 on the sidewalk.
I read on the internet that Apple can replace the screen for cheap.
How much would Apple replace it for?
And my iPhone lags and glitches a lot, would they just swap me for a new iPhone 5?

Don't go to any third party places to try and get the screen fixed unless you plan on sticking with that phone! If not, go atraight to apple with the receipt (if you have it, you don't necasarily need it) and they should swap it out for a refurbished one. They don't normally just fix the sceeen. If you have the screen fixed by someone else, they won't take it back.