Deleting comments in blogspot isn’t as intuitive as deleting a comment in say, wordpress. One more thing, you can’t edit a comment already published in blogspot, the only course of action you are have is to either accept or delete the comment. Here’s the instruction which I figured out my own how to delete a comment in blogspot:

1. Sign in to your blog.
2. Click the comments link located at the bottom of your post.
3. Comment trail appears. You can see located at the lower portion of the comment is a gray trash can icon. If you want to delete this comment, click the trash can icon.
4. Confirmation message appears. Click ok to confirm.