Generally, a parting is done as a ritual, but you can do one on your own.
The main idea is to visualize the bond between you two and then visualize it breaking. You can really do this in any manner - with a string to cut symbolizing your ties are severed. You could burn something that you feel symbolizes your connection to this person and that as it burns the connection is gone. There are other ways, but these are the ones I prefer...
Good luck in your endeavors!