How do you change the port on your computer in which you connect headphones?

I have to connect my headphones to the port at the back of the PC for them to work but i want to connect them to the port at the front. The front port does not work and i need to know how to change which port the computer recognises. The headphones used to work in the front port but don%26#039;t anymore.|||You must add some cord to make it works, contact professional for it, because it may need to modify something in soundcard