How to deface website

Question

which is the best way to deface a website easily?

Answer 1

Why separate yourself from the full experience? Delete your own hard work. You have your own permission and you know how you think, so you can ensure you must to recreate your blood, sweat and tears from what you remember, no backups.

Totally the best experience.

Answer 2

if your done reading Kirk's non sense... XSS(Cross Site Scripting) is the vulnerability your looking for when defacing a website.
but before you dive into destroying people's life. learn JavaScript and HTML(Hyper Text Markup Language).

But I take no responsibility for your actions.
and the website must have the vulnerability.