Go to the files' saved location on your computer (ex. MyDocs, Downloads folder, Shared Drive, etc.). If the file is not saved on the computer, save the file to your MyDocs.
Right-click the file you want to open.
Select the "Open with" from the drop down menu, then "Choose Another App."
Choose the app that you want to use to open this file type. To make this app the default program select "Always use this app" then select OK.
Note: You can see what the current default application is by looking under "Keep using this app."
The file will now open in the selected program.