Changing Start up screen is easy. You have to follow some steps:
1. Go to program files
2. In C:\Program Files\Autodesk\Maya2014\icons , folder search for "MayaStartupImage.png"
3. First make backup for this. Just copy it in other safe directory.
4. Now edit or make another startup image which you want to pop up during starting Maya 2014.
5. Save it as same name and same ext. That is MayaStartupImage.png
6. Replace image with original image in Same directory C:\Program Files\Autodesk\Maya2014\icons.
7. And now start maya. You will find Splash screen replaced
