I just bought a new knob for my Silver Surfer, can I change it myself or do I have to bring in it to get it swapped?

You can easily swap your knob.  Carefully grab the knob with your thumb, pointer and middle finger and pull.   It can help to use your fingers to push between the knob and housing as you pull, essentially prying the knob off.

Do not twist and pull, or you could twist the dimmer and break it.