How to open and view a deadlock graph .xdl file with SSMS ?

Solution 1 :

On the File menu in SQL Server Management Studio, point to Open, and then click File.
In the Open File dialog box, select your .xdl file & click open.

Solution 2 :

Go to the directory, you have saved your deadlock graph .xdl file.
Right click on .xdl file > Go to Open With Option > Select SQL Server Management Studio