Remove "image" in the title and "posted on"

Hi, I use the Twenty Eleven 1.3 theme, but I want to remove the text “IMAGE” over the title, when i post a picture.
And I want to remove the “posted on” -box.

Look at this link to see what I mean:
I want to remove the text and the box where it is a red circle

Thanks! Sorry for my english, hope you understand it 🙂