is it possible to chane iphone battery at home

NO. You can't even buy an authentic Apple Battery as Apple does NOT sell parts. iPhone has NEVER been a do it yourself repairable device. And people come here everyday asking how to fix their phone after buying aftermarket batteries and things stop working on their phones. The answer is Apple won't ever touch a device after it's been tampered with, we can't help and they likely need to buy a new phone.

So, if you need a new battery, schedule a battery replacement at your Apple Store Genius Bar or Apple Authorized Service Provider and for either $49 or $69 (depending on phone model), and have an authentic battery installed which will come with a warranty.

Apple does not sell iPhone parts, including batteries, for self installation.

Make an appointment at the Genius Bar of your local Apple Store or take it to your local authorized service provider to have the battery replaced.