How can I replace my iPhone battery in less than 20 days?

My battery is draining faster than usual and I wanted to get it replaced but I only have one Apple store in town which has tons of bad reviews about peoples experiences with their battery replacements and also on twitter there's a mix of people just getting sent new phones or they broke their phone and charged them for it. I also don't want to do it myself because I'm afraid I'll break it. I really need to fix this problem before the end of the month.

Unless you have a friend capable of doing it, your only option would be to find a repair store near you that offers iPhone battery replacements

Iphones are not meant to have their battery changed. Apple Stores are the only ones authorized to do it.
you are avoiding your only option.