@gauravchaud4197 let us know the exact model number for your laptop (I assume it's an XL21) If so, your battery should be a 537077-351P. to get to the battery you will need to remove the bottom cover.
Since iFixit does not yet have a guide for this, use something like [https://www.youtube.com/watch?v=ob13fObmrMg|this video] to get into your laptop to remove the old battery.
While you work on your laptop, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has a device with the same issues as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.
Repair is War on Entropy!