How can i add nofollow to all my Developed blogspot . i havent put nofollow to any of the 100 indexed page yet.. how can i change it to nofollow ?
wherever you have a link (may it be comments, link to other blogs, etc) you put a rel="nofollow" tag in the a:href. But reconsider the idea of putting a nofollow. It just shows a bit disrespect to your readers, because you don't send any search engine robots to them. It's a good tag to use, but use it wisely.
All comments are nofollow by default. As robojiannis rightly says there's no way of doing it other than by manually going through all of the posts - not that I'm aware of anyway. I would just leave it.