From within the permissions tab:

To publish or unpublish everything in the project

 1   Within the Content Access tab, select Edit > Live (you can also choose Draft but published items do not appear in your index for reviewers unless a minimum of 'View' permissions have been applied).

 2   Select Publish in the top menu, and choose Publish All or Unpublish All.

To publish or unpublish individual files

 1   Within the Content Access tab, select Edit > Live (you can also choose Draft but published items do not appear in your index for reviewers unless a minimum of 'View' permissions have been applied).

 2   Click the filter icon under the Status column and select Published or Not Published. Only 200 documents appear at a time. Repeat step 3 for each page.

 3   Select files by ticking their checkbox, click More Actions and select Publish or Unpublish.