If you want to change alternative port for MSSQL remote access, please perform following steps :
Go to Start -> Programs -> Microsoft SQL Server -> Configuration Tools -> SQL Server Configuration Manager.
Under SQL Server Network Configuration -> Protocols for SQLEXPRESS -> TCP/IP -> under protocol tab Enable it.
-> Under IP Address Tab give Port Number in front of TCP Port field.
Click on Apply & OK.
Restart SQL Services.
Now you can login to your SQL Server using your given port.
Hope this helps you.