There is detailed documentation on the steps you should take for updating from an earlier version of GraffitiSuite Desktop Edition. An overview is:

1. Always backup your project before attempting an in-place upgrade
2. Download the latest version of GraffitiSuite from the Account page.
3. Open the project you wish to update.
4. Select the App object in your project.
5. Save and close your project.
6. Reopen your project.
7. Delete the GraffitiSuite folder from your project (or the GraffitiSuite classes you intend to update).
8. From the extracted download, open the demo project.
9. In the demo project, copy the GraffitiSuite folder (or the GraffitiSuite classes you intend to update).
10. In your project, paste the previously copied GraffitiSuite folder (or the GraffitiSuite classes you intend to update).
11. Save the project and close.
12. Reopen the project.

See also notes for each step and a video walkthrough.