I was having the same problem. This post helped me out:

To delete a file ...

1. In Contribute, browse to the file you want to delete.
2. Select File > Delete Page.
>> You are prompted to confirm the operation.
If Delete Page is disabled in the File menu, the permission group
needs to
allow users to delete files. This option is available under Folder/File
Access
in the permission group settings.

Note to Contribute 3 users: the Delete Page item is at File > Actions
> Delete
Page.


kaila2 wrote:
> This question hasn't been answered. I also want to clean up my files
as showing up in search engines. Using contribute 2.