For some of you this will be so "last season" but there are still a few out there who still want to know if this can be accomplished. There can be several ways to modify Revit families but it always seems that the elevation markers and section markers are always a hot issue.
You can modify these markers even though we have all been told that we cannot modify System Families. Still the rule of system families is; you cannot directly open and edit the family within the drawing. You can open the family to edit from the Application Menu or the big R in the upper left hand corner or by going down to Families in the Project Browser and expanding the Annotation category and finding your family there.
Once you make changes make sure to save it in a different location so you do not overwrite the out of box family then load it into the project.
Note: If you rename the family you will have to go into the settings and specify that you want to use a different named marker.