Replacing my MBA11 2011's Battery

My Problem

The battery's health dropped to below 30% within 6 months, and the warranty is out.

My Fix

It was quick and straightforward fix, all thanks to the guide from you guys.

My Advice

Good battery send by you guys, it was better than 100% health when I first use it. One week down and it dropped to 97%. I'll monitor from here on.