Being a Contribution Mananager you are responsible for managing the information in your contribution. Your are given contribution management access by either the Conference Manager, Session Manager, the existing Contribution Manager and possibly the Session Co-ordinator.
You can access your contribution by selecting 'timetable' from the left hand menu and finding your contribution if you are the manager of that contribution you will see a small red pen in the top right corner this will take you to your contribution management area.