You can access any of your CVs from the main menu entry "My CVs". Simply click on it's name and you'll get to the CV edition page:
To modify your personnal or HHRR data, you must access your profile. Your profile is unique, belongs to your user and it's data are used in all the CVs.
You can edit the CV summary details from the Summary tab clicking on the "Edit CV data" button.
From here you can edit your detailed information, you courses, experiences, knowlkedges, languages and additional informations. There are only a few required fields (with yellow background). This way you can begin inserting your CV and you can come back and complete it later.
Only you can modify your CVs, and you can't delegate this task in any other user (unless you give him your credentials).