Delete a part of a backup

Hi,

I updated my iOS from iOS 6.0.1 to the latest version (6.1). Before the update, I made a backup to keep my information. My iPhone 4S was almost full. After downloading the new version the size of the iOS 6.1 + my backup is greater than the capacity of my phone. Is there a way to access and then delete a part of the backup (e.g. some photos or videos)? This can help to not lose my important stuffs.

Regards,

Ammar