How do you remove the 'return' link at the top of a gallery attachment page?

Does anyone know how to remove the ‘return’ link at the top left side (under the header) of a gallery attachment page in the Twenty Ten theme?

This is the link to one of the pages I need to change https://mountprospectstudio.com/wordpress/?attachment_id=110

I want to remove the link that says ‘portfolio’ since there is already a link to the portfolio page in the menu, and I also want to lessen the gap between the image and the header. I would be so grateful for any assistance in how to do this.

Thanks, Bria