How to stop Firefox opening xml files and get gedit to open them instead

"Change this way

Right click on a xml file
Choose ""Properties""
Click on the ""Open With"" tab
Choose your new default editor

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(or )

Change the default ""Open with"" program for a file type

In Nautilus, right click on the file and choose Properties from the menu that appears. The Properties dialog opens.
Click on the Open With tab. A list of applications appears.
Select the default application you want for the file type. If the application is not on the list, use the Add button to add the application to the list."