Drupal 7 views and pages

In regard to my previous post on roles and permissions, it seems that I cannot grant permission for a reviewer to modify content from another user. Is there a way to allow this please?

I have given the role of Reviewer, permissions same as the Calendar Editor and included "Bypass access control" and "Administer Content" none of this helps.

Content may be provided by any or all of 6 editors over a 3-4 week period. I need for the reviewer to be able to review and alter any content of this specific content type from any or all of those users as soon as the notification arrives in his email.

I would really appreciate help on this please thanks Roger