When you're at work, is there someone driving you nuts?  Do you find yourself irritated every time you need to speak to them, or their name pops up in your email box?  Start getting curious about that irritation you are feeling. Ask yourself why this person is getting such a reaction from you, and notice your behavior in response to them. 

Now, take a look at what it is you want from this person.  Assuming that you want to keep your current job, do you want to be friends with this person?  Do you just want to make it through the day without spending so much negative energy on them?  Figure it out.  Now you can brainstorm ideas on how you can change your reaction to this person which will, in turn, completely change your relationship to them.

Remember, if you have lots of negative energy cycling through your thoughts and body each day, you're probably helping to manifest the current situation, and feeling pretty depleted every day.  If you change your intention, you can change the energy into something more positive, and invigorate yourself. 

Always keep that positive vision in your mind where you have the successful working relationship you want with this person, so you can take action towards it every day.