How to make Google deindex the indexed pages?

I want to make one of my sub domain to de-index all the indexed pages at once.
I tried from webmaster tools, but failed. Any Answers?

 

Use a common meta tag "<meta name="ROBOTS" content="NOINDEX,NOFOLLOW">"
That'll take care of it.

 

if you failad in webmaster tools you MUST block google with robots txt befor you ask them to remove a page or a site in google and thay will remove it

 

Yeah, I blocked google via robots.txt but still it was saying "failed to remove"
here is the link to be deindexed.

 

I am curious to find why you want to de index the Pages? Just a question no offense

 

I removed the video script from my site and I don't want those pages now in google index...that's it

 

set robots.txt for that subdomain
also you can put some script to detect the bots and redirect.

you have to wait until google clear the pages from their index. you cant do anything instant on that.

 

Yeah, I already set the robots.txt

Can you please check that once..Thanks