Open the Job by going to Jobs > View Jobs > Select the Edit pencil for the intended job.

Or Scheduler > Click on intended job > Select Edit Job.

To change the order, you can change the Primary Assignee in the Assign To field. Then remove any assignees from the Additional Assignees you don't want there and add other Users in the order that you prefer. To remove Additional Assignees, just click on the 'x', which is beside the name of the User(s).