1) Install Navi-X from the linuxsat-support addons panel.
2) Map the mute button to ContextMenu as explained here -> [How-To] Context Menu and Submenu in Xbmc
3) Launch Navi-X
4) Select the media you want to watch
5) Push mute button to access Submenu
6) Select Set Default Player
7) Select PAPlayer
8) CLOSE THE OPTION MENU
9) Select again Set Default Player
10) Select Auto Select
11) Close the menu
12 Run your file.
Thanks shiro