Breaking up with a Taurus tends not to be easy because the longer you're in the relationship, the more entwined the Taurus becomes into you and into maintaining the stability of it.
Taurus is a person who wants to be in something that's loyal and forever. Longevity is a key in Taurus's relationships.
To begin with, you have to start detaching if you're not going to come right out and say, "I wish to leave". You have to start detaching emotionally, not pay attention, be aloof, be away a lot. The Taurus also is someone that needs a sense of class and elegance in its surroundings.
If indeed you start getting sloppy, you don't care what you wear, you look grimy, you don't pay attention to the niceties, you don't have nice manners, the Taurus will also start detaching from you.
Basically the key to breaking up with the Taurus is to work with the fact that the Taurus is very attached and you have to detach to make the Taurus realize that this relationship is not stable.