Take a piece of paper. Write down all the reasons you want to end this relationship. Every single one. Then color in the paper black. Then take a small box and in it put any crystal you like. Light a candle and then light the paper in the candle flame. As it burns, repeat:
"For all good there ever was between (your name and his), shine light
For all ill that ever existed, to ashes burn,
So that the cycle of love's summer may like autumn-time, turn.
Place the ashes in the box with the crystal, tying a ribbon around the box to seal it. As you tie the ribbon feel your resolve tighten. As long as you have this box with you, it will remind you of why you want to break up. The crystal will help to keep these messages vibrating.