I would like to have a different logo for checkout pages. How do you setup an override?

My logo is a banner . and I would like the banner to show relevant information on shopping card , shipping and payments.

What is the best way to do this. Can someone help me with the logic ....which files need changing .... or overriding ...can this be accomplished without changes to the core code.

Example website is http://morgan111morgan.com
Thank you in advance
Onesimpleman