Change the MSSQL Port Number
In order to change MSSQL port, follow the steps below.
Login to server via RDP
Click on Start
Click on All Programs
Select SQL Server Management Studio
Click on Configuration Tools => SQL Server Configuration Manager => Expand SQL Server 2008 Network Configuration => Click on Protocols for MSSQLSERVER => Right Click TCP/IP and click properties
Drop down to the bottom of the window and change the paramenter "TCP Port" to the desired port you want.
Please don't forget to add this port in firewall.