You can update jobs as well the job screen as the planboard in: Backoffice -> Dispatch
(click to enlarge)
To edit the job details you can drag a triangle to the [edit] button which is next to the [remove job] button in the upper right corner of the left frame. The job details will appear and can be changed.
In the right frame there is a small blue edit symbol which can be clicked to change job details from that frame.