Open NAV object designer and create a new codeunit.

In the OnRun trigger, add a single line of code:

        MESSAGE('Hello World'); 

Click Save, fill in the ID and Name fields: 50003 HelloWorld, close the code editor.

Select the codeunit 50003 in the object designer and click Export in the File menu.

Choose the folder where you want to export the codeunit to and name the file COD50003.txt.

Select Text Format (*.txt) in the File Type drop-down list and click Save.

In a file manager, locate the file COD50003.txt and open it in a text editor. This is how the exported object looks in a text editor:

        OBJECT Codeunit 50003 Hello World 
        { 
          OBJECT-PROPERTIES 
          { 
            Date=22.07.16; 
            Time=23:44:09; 
            Modified=Yes; 
            Version List=; 
          } 
          PROPERTIES 
          { 
            OnRun=BEGIN 
            MESSAGE('Hello World'); 
            END; 
 
          } 
          CODE 
          { 
 
            BEGIN 
            END. 
          } 
        } 

In the object text locate the line MESSAGE('Hello World'); and replace the message text, MESSAGE('Exported NAV object');.

Save the object and close the editor.

Return to NAV object designer, click Import from the File menu, select Text Files in the file type filter, and choose the file COD50003.txt.

Click Design in the object editor window and review the object code. It contains code modified outside of the C/AL editor.

In the object designer, select the codeunit 50003 we created in the previous step and click Export in the File menu.

Select Dynamics NAV Object Format (*.fob) in the File Type drop-down list.

Choose the folder where you want to export the codeunit to and name the file COD50003. It will be automatically assigned an extension .fob. Save the file.

Back in the object designer click Design to edit the codeunit and replace the message text with the empty string: MESSAGE(''). Then save the codeunit and close the code editor.

In the object designer, click Import from the File menu. In the Import Objects dialog, select Dynamics NAV Object Files in the file type filter, locate the file COD50003.fob, and click Open.

C/SIDE will warn you that there is an object with conflicting versions in the database. Click OK to switch to Import Worksheet:

Click OK to import the object replacing the codeunit existing in the database.