Can I edit comments I left on someone else’s blog?
No. It is not possible to edit or delete any comments you have left on other WordPress.com blogs. Blog owners are in full control of the comments on their blogs, so you can try contacting the blog owner and ask them to edit or delete a comment for you. If the blog owner has not posted any contact information, you can try leaving a short comment asking how to contact them directly. http://en.support.wordpress.com/my-comments/#can-i-edit-comments-i-left-on-someone-elses-blog