I'll bet you've seen plenty of movies, where boy meets girl, they fall in love, and live happily ever after.
  Right?  At some point, though, in most of those movies, the couple breaks up.
  BUT they get back together!  Although your life isn't a movie, you can get your ex wife back, just like in the movies.
  How? Sometimes, in a breakup or divorce, the couple cuts each other out of their lives completely.
  This is completely normal, and is all a part of a person's way of dealing with pain.
  After the initial anger and hurt, though, is your chance to get her back.
The two of you probably have a mutual friend or two.
  If so, you could have a friend initiate the first meeting, or they can tell your ex that you would like to talk to her again.
When you do talk to her, don't bring up your past relationship, in any way.
  You can talk about it later, but not when you first talk to her.
  At first, keep the conversation light, and comfortable.
  Just talk about how she's been doing, etc.
Next, try a little harmless flirting.
  If she responds, then you are on your way to getting her back.
  She may not respond right away, but that's ok.
  Stay friends with her, you will find that she opens up more freely as some time passes.
  Then you can try flirting again, and see what happens.
Third, don't be pushy.
  That is what most of us do, but that will scare her away.
  Take you time, be friends, have some fun.
  The more fun the two of you have together, the better you will both feel.
  The better you feel with each other, the more you will want to be around each other.