Why Do You Want to Replace iPhone Battery?
Case 1: When the battery reaches the end of its useful life, Apple intends for one to return the entire mobile to the company to have the battery replaced for a cost of US$79 plus US$6.95 shipping (and applicable sales tax).
Case 2: iPhone accidentally got water or oil damaged and you need to take down the battery to get it fixed.
Case 3: Unfortunately to get an iPhone with a battery that can be kept for a short period of time even after a full charge.
Case 4: iPhone got an unexpected destroy (whether hardware or software destroy) and you are looking forward to fixing it by replacing battery.
How Do I Replace Battery in iPhone 5s?
Note: It is similar for iPhone 5 and 5S models. This article, I will take iPhone 5s as the example. Hope it helps.
Like all previous iPhone models, the battery in the iPhone 5S models is not intended to be replaced by an end-user.
For those with modest technical skills, patience, and a steady hand, battery self-replacement is possible, although professional installation is strongly recommended.
Things You Should Know before Replacement
1. Be sure iPhone is powered off.
2. Be aware that replacing battery by yourself has risks to damage iPhone.
3. Get an iPhone tool kit which contains screwdriver and other needed tools. You can buy it from Amazon or lend it from your friends.