In order to upload files your account has to be setup to allow it and the file must be less that 100M. If that's the case here are the steps to upload a file:
If your file was uploaded in the “My Downloads” section, you can always go and retrieve it or edit it. This is not available for the other category. Each subsequent time you upload a file you should go to the original file and “edit it” to put up the new version. It's very useful to keep track of versions and you can retrieve older versions later. We try to use the long description box to keep track of some notes about the updates to each version.
Only the person who originally uploaded a file can re-upload or edit information about that file. Here's the steps:
NOTE all older versions of the file are kept and are still easily accessible!
The whatIf? staff and others in your group with access to your “My Downloads” will be able to download the file you uploaded and previously uploaded versions of the same file by: