HTC DESIRE 816 Battery removal.

[yusuf.khan.00]

I am using HTC Desire 816. My phone is stuck. It won't start. It won't even boot in fastboot. All I am getting is a dead screen. When I press volume up+power button, it shows the Boot screen (HTC Logo) but then it just dies. Phone is not in warranty. I read here that battery disconnection and then reconnecting it solves the problem, but I do not know how to replace the battery. So, if someone can help me out, that would be great.