1. Using Finder, locate any PDF file. Right-click (or Control-click) the PDF file and select ‘Get Info’ from the menu you’ve opened.
2. Under the heading ‘Open with,’ the current default application for opening PDF’s is listed (which will most likely be Preview). If there is no application listed you may need to click the triangle to the left of ‘Open with’ so that it points downward to reveal the current setting.
3. Click on the application list to open a drop-down menu displaying additional applications. In this menu locate the most recent version of Adobe Reader and select it.
If Adobe Reader is not listed you may not have it installed (check by selecting Other …. and navigating through your Applications folder to locate the icon for Adobe Reader – if you do find it, click to highlight it and then click the Add button).
4. Back in the information window click the ‘Change All’ button so that all subsequent PDF files will be opened by Adobe Reader
5. Click the Continue button to confirm that you’d like to change your settings. Now all PDF files will be opened by Adobe Reader.