Revit area plans adding new types and references (Gross and rentable)

Ever had any stubborn text styles that wouldn't delete? I did- so I went to Boost Your BIM - Scrubbing Out Dimension Styles and adapted the code there to substitute one text style for another in my first useful macro! 

Start with a sample of text with the text style you want to replace, also add a sample of text style you want to match.

On runing the macro- it prompts in the STATUS BAR (tough to see - working on that) to select a text to replace, then the ext to match. Once completed you can run a purge and Voila! those peskt text styles should be available to purge!

using System;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Collections.Generic;
using Autodesk.Revit.DB;
using Autodesk.Revit.DB.Architecture;
using Autodesk.Revit.DB.Events;
using Autodesk.Revit.UI.Events;
using Autodesk.Revit.UI;
using Autodesk.Revit.UI.Selection;
using Autodesk.Revit.ApplicationServices;

        public void TextSytleScrub()
        {
            Document doc = this.ActiveUIDocument.Document;
            UIDocument uidoc = new UIDocument(doc);
      
            // Prompt user to select a -text- with an unwanted style
            TextNote selected = doc.GetElement (uidoc.Selection.PickObject (ObjectType.Element , "Select -text- with style to scrub.")) as TextNote ;
            // Get name of the -text- style of this -text-
            string toScrub = selected.TextNoteType.Name;
      
            // Find the -text- style named "Default" which will be used to replace the unwanted style
            // There must be a style named "Default" for this command to work

      
            TextNote replacement = doc.GetElement (uidoc.Selection.PickObject (ObjectType.Element , "Select -text- with replacement style.")) as TextNote ;
            // Get name of the -text- style of this -text-
            string toreplace = replacement.TextNoteType.Name;
          
            TextNoteType defaultType = (from v in new FilteredElementCollector(doc)
                                        .OfClass(typeof(TextNoteType))
                                        .Cast<TextNoteType>()
                                        where v.Name == replacement.TextNoteType.Name select v).First();
          
            using (Transaction t = new Transaction(doc,"Change -text- style to default"))
            {
                t.Start();
                // loop through all -textnote- with the unwanted style
                foreach (TextNote textnote in (from v in new FilteredElementCollector(doc).OfClass(typeof(TextNote)).Cast<TextNote>()
                                      where v.TextNoteType.Name == toScrub select v))
                {
                    // change the -textnote-'s style to the default style
                    textnote.TextNoteType = defaultType;
                }
                t.Commit();
            }
      
            // Text in unplaced groups will not be found by the code above.
            // So we need to place an instance of each of these groups, find any -textnote- in the group, and change their style if needed
            foreach (GroupType groupType in new FilteredElementCollector(doc).OfClass(typeof(GroupType)))
            {
                // if there are already instances of the group then skip to the next group type
                 if (groupType.Groups.Size > 0)
                     continue;
                 using (Transaction t = new Transaction(doc,"Change -textnote- style in unplaced groups"))
                 {
                    // use this flag to track if any -textnote- have been changed
                    bool flag = false;
                    t.Start();
      
                    // place an instance of the group
                    Group newGroup = doc.Create.PlaceGroup(XYZ.Zero, groupType);
      
                    // loop through all members in the group
                    foreach (ElementId id in newGroup.GetMemberIds())
                    {
                          // identify any -textnote- in the group
                          TextNote textnote = doc.GetElement(id) as TextNote;
                          if (textnote != null)
                          {
                              // check if this dimension has the unwanted type
                              if (textnote.TextNoteType.Name == toScrub)
                              {
                                  // change the dimension type to the default type
                                  textnote.TextNoteType = defaultType;
                                  flag = true;
                              }
                          }
                    }
                    doc.Delete(newGroup.Id); // delete the newly placed group
                    if (flag)
                          t.Commit(); // commit this transaction if any -textnote-s were changed
                    else
                          t.RollBack(); // no -textnote-s were changed, so throw away the entire transaction
                 }
            }  
        }