To convert from DirectX to OpenFX, you would need to do the following:
1. Have the DirectX version installed.
2. For every title created using DirectX, open them and do a File – Save As and save each to their own name
3. Now uninstall the DirectX version and install only the OpenFX version.
4. Now replace the DirectX versions with OpenFX versions. When adding the new OpenFX title, then do a File – Open and open the saved title.
For Vegas Pro 10 and newer, it is certainly recommend that you install only the OpenFX version.
Edward Troxel