To change the text of a model text element, select it and use the Edit Text tool on the Modify tab. 
Note:  Model text saved with a family and loaded into a project cannot be edited in the project view. 
-  In the drawing area, select the model text. 
- Click Modify | Generic Models tab Text panel Text panel  Edit Text. Edit Text.
- In the Edit Text dialog, change the text as desired. 
- Click OK.