Can I just replace this part or might the...

Just wondering if we can just go and get the replacement part for my computer? Forgive me I am not a computer wiz and hubby is at work. But the area on the computer where stick your memory stick or a usb cable has been malfunctioning a lot on this computer. You know like where you stick the memory stick from you camera to upload pics from it. Well lately you have to fight with it to get the computer to recongize there is something there. The light won't come on. And now the the area where you stick the usb cable is not working all the time either. Can we just replace those part. Or might there be another underlaying problem. This computer is only about 3 years old it is a compaq presario