Converting a PDF File to Another Format in Preview
The default viewer for PDF documents in the Mac OS X is the Preview app. So, unless you have changed your default settings, PDF documents should automatically open in Preview.
1. Open the PDF document in Preview.
2. Click File and choose Save As… from the drop-down menu.
3. Change the file name at the top of the Save As box if you want to. Browse the files and folder structure to the location where you want to save the document.
4. Click the field next to Format to drop the menu down and see the formats you can choose from. The choices are GIF, ICNS, JPEG, JPEG-2000, Microsoft BMP, Microsoft Icon, Open EXR, Photoshop, PNG, TGA or TIFF. Click on what you want and then click Save.