Open With (New File)
You can open a document in one or more editors by clicking Open on the File menu and then clicking File. In the Open File dialog box, select the file, click the Open arrow, and then click Open With. In the Open With dialog box, in the Select a program to open list, click the preferred program, and then click Open.
Select a program to open
Lists the editors available in Microsoft Visual Studio for the selected type of file. Choose the editor with which to open the document from the list displayed, or click Add to include a new editor in the list.
Click Open to open the document in the selected editor.
Click this button to add a program to the list under Select a program to open. You can either type the file path to the program in the Program Name field or browse to the program's location by clicking Browse. In Friendly Name, enter a program name to display in the list under Select a program to open.
To remove a program, select the program and then click Remove.
Set as Default
To specify a default editor (and language encoding options, if applicable) for the type of file selected, choose a program from the list under Select a program to open and then click Set as Default. The next time you open this type of file in SQL Server Management Studio, the document will open in the new default editor.