In order to change one service port number in Windows systems, you need to change the services file in the %SYSTEMROOT%\SYSTEM32\DRIVERS\ETC folder (usually c:\windows\system32\drivers\etc).
For example, I need to change the udp port number for the SNMP service. To do this edit the file c:\windows\system32\drivers\etc\services with notepad, or any other text editor, and in the line:
snmp 161/udp #SNMP
snmp port_number_you_want/udp #SNMP
Save the file and restart the SNMP service in the services.msc.