Erase a Member of a Collection Object

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;

[CommandMethod("RemoveMyLayer")]
public static void RemoveMyLayer()
{
  // Get the current document and database, and start a transaction
  Document acDoc = Application.DocumentManager.MdiActiveDocument;
  Database acCurDb = acDoc.Database;

  using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
  {
      // Returns the layer table for the current database
      LayerTable acLyrTbl;
      acLyrTbl = acTrans.GetObject(acCurDb.LayerTableId,
                                   OpenMode.ForRead) as LayerTable;

      // Check to see if MyLayer exists in the Layer table
      if (acLyrTbl.Has("MyLayer") == true)
      {
          LayerTableRecord acLyrTblRec;
          acLyrTblRec = acTrans.GetObject(acLyrTbl["MyLayer"],
                                          OpenMode.ForWrite) as LayerTableRecord;

          try
          {
              acLyrTblRec.Erase();
              acDoc.Editor.WriteMessage("\n'MyLayer' was erased");

              // Commit the changes
              acTrans.Commit();
          }
          catch
          {
              acDoc.Editor.WriteMessage("\n'MyLayer' could not be erased");
          }
      }
      else
      {
          acDoc.Editor.WriteMessage("\n'MyLayer' does not exist");
      }

      // Dispose of the transaction
  }
}

출처
http://docs.autodesk.com/ACD/2010/ENU/AutoCAD%20.NET%20Developer%27s%20Guide/index.html