To move a unit up or down, click and hold the drag handle. Move the unit to the desired spot in the course.
There is also a drag handle on all lessons and activities.
Be cautious of the lessons within the unit because you might be moving lessons that are pre-requisites to other lessons. There are not flags to tell you if pre-requisites are now below lessons that should be later.
Also, if an assessment is placed in the middle of a unit or if items are bypassed via prescriptive testing, the assessment might automatically be bypassed because of the limited number of questions available. Students will be sent to the next activity.