Severing the ties bound when you took your vows with your significant other can be as simple or as elaborate as you like. I suggest simply visualizing him/her as you remember him/her from your wedding day.
Visualize a white cord tied first to your waist and then to his/hers.
Next,call out to the God/ess,
We took our oaths freely
Each promising to cherish, love and protect.
By your hand, you broke your oath.
By my hand, our bond is severed.
Visualize cutting the cord between you.
You are no longer psychically bound to him in this life, or the next.