You can use the Unlink from Schedule button to unlink points from a schedule, after which the points' status will be schedulable.
Open the Schedules drop-down from the Available Trees menu.
A list of schedules is displayed.
Select a schedule.
A list of points associated with the schedule is displayed.
Select the point to unlink or unassign from the schedule.
Select the Unlink from Schedule button.
The button turns gray, indicating that the point has been unlinked from the schedule.