Go to "Edit Profile." On the "background" tab, you can upload your CV file. Just click upload, find the file and upload it.
Note: Give your file a meaningful name. Don't upload a file "resume.pdf" as it may overwrite another resume/CV of the same name. We recommend you name your file Lastname-Firstname.filetype.
Be sure to check out the "Preferences" tab to update your privacy settings. This allows you to opt-in to sharing information, including your CV, with other users.