It can be done.
I have done it. I wanted my girl back, after she cheated on me, and the experience was life changing and eye opening. I went through a period of rapid maturation, and in the process learned the true meaning of self reliance and understood the co-dependant nature of our relationship was unhealthy in that I was unwilling to risk 'losing' her, even when her actions actually made her undeserving of me.
Ironically, when I finally matured enough to make the hard decision of cutting her out of my life and moving on in spite of the pain that it would cause me in the short term, she took a great notice of my self sufficience and fell back in love with me.
Now she is the one learning how to live without the one she loves. If she hadn't cheated on me, it would all be different. I could afford her another chance. As it is, I could have taken her back on ANY terms - I had complete power. She begged and pleaded me time and time again, leaving heart wrenching messages that flooded me with memories of our best moments and a deep selfless desire to protect her and even guilt that I could just kiss her and make her happy, but since I believed that it truly would not be for the best I made the much harder choice and told her that I could not do it.
What changed the nature of our relationship wasn't a technique I read on the internet - it was a complete overhaul of my beliefs, and it was permanent. If I had decided to take her back, she would have seen a side of me that she never saw before. If you want to save a relationship, you have to truly change yourself.
I recommend reading Rollo Tomassi's thread about power dynamics in relationships here
http://www.sosuave.net/forum/showthread.php?s=&threadid=77115