1. Go to whois.net and look up the domain point of contact

2. Call them and find out what datacenter the site is hosted in

3. Break into the datacenter and locate the server(s) for said site

4. (A) Pull the aforementioned server out of the rack and (B) throw it to the ground. Use force

5. Repeat step 4(B) until you grow weary or you are arrested

Note: this is a "cross browser" method - it works for FireFox, Opera, Netscape, and IE