Is the ethernet port is part of your board? If so, you will need to get the schematic of the board itself and if your are good with a soldering gun and know what you are doing, yes you can replace the port as it is soldered to the board itself.
Make a mistake, get a new board. Risky
Honestly, getting a seperate card would be the way to go if you're board is working fine outside of the Ethernet port. Especially if it's a high end board.