✅ How to change of property without setter?

var reportObjects = _report.AllObjects;
for (var i = 0; i < reportObjects.Count; i++)                                                 
{                                                                                               
    if (reportObjects[i] is TableCell)                                                      
        ((reportObjects[i] as TableCell)!).Font = new Font("Calibri", 20);                
    if (reportObjects[i] is TextObject)                                                     
        ((reportObjects[i] as TextObject)!).Font = new Font("Calibri", 20);               
}