Step 3: Create an SPN for SQL Server in above mentioned link. Syntax is also given there. Following is the quote from above link,
SQL Server only uses Kerberos if the client uses the TCP/IP protocol to connect to SQL Server. For example, if a client uses the Named Pipes protocol, Kerberos is not used. If you have multiple instances of SQL Server on a computer, you must configure a Server Principal Name (SPN) for each instance of SQL Server because each instance of SQL Server uses a unique TCP-IP port.