From the Job Checklist page

Under the blue header labelled 'Rooms' press  \/ to expand the box . This will give a list of rooms 

Press the folded paper with a pencil on the right to expand edit options for each rooms 

* To reorder rooms press on the four blue lines on the right and slide and drop and drag the room to the wanted position

* To delete a room simply press the bin on the right - this will then give you a warning box 'are you sure you want to delete this room' -select YES or NO