1. Select the picture file in the Finder.
2. Chose File > Get Info. The Get Info window displays.
3. In the Open With area, choose the target application (such as Photoshop or Illustrator) from the drop-down menu.
4. Click Change All.
5. Click Continue.
1. Right click on an image.
2. Select 'Open With' and choose the application from the list.
3. If the list doesn't show the required application, click 'Choose Program' and you will see list of more applications.
4. You may check the box 'Always use the selected program to open this kind of file to have all files of same format.
5. Click Ok.