Those who "want my wife back” need to know this word: HUMILITY. You better believe that it is going to take some crawling and some begging if you are going to get her back. You can't start feeling that you are too good to come back to her on your knees. If she is still mad at you, you probably deserve it.
The first thing you need to do is admit that you messed up. Don't make excuses for it and don't try to cover it up. If she starts telling you how bad it is, you have to agree with it. This is no time to try and defend what you did. Don't lie about it, you have to be honest. Lying will only get you in more trouble. Also, don't try and gloss over it saying it wasn't that big of a deal. If it cost you your marriage, then obviously it was a big deal.
The second thing that you are going to have to do is not just tell her that you are going to better. You may have tried that before but didn't get better. You have to make her believe it. It will take more than words to get her to believe it. If there is something that you did that you should stop doing then you probably need to take steps to stop it.
For those of you that have a problem with drugs or alcohol, you better go and get some help. You should be working on that before you start telling her that you are trying to change. If it has to do with anger issues, get enrolled in anger management classes and start taking them. Whatever problem it is she says you have, you better be making steps to get it corrected. If you really “want your wife back” you better get serious about making those changes.
You may find this to be a lot of work and that is because it is hard work. You may think that you are just fine the way you are but “the way you are” caused the breakup to happen in the first place. The way you were wasn't good enough.
Your pride may cause you to believe that you are too good to do a lot of the above but to get your wife back you need to lose your pride and learn a lot of humility. You can't let your pride get in the way of doing what you need to do to when you “want your wife back”.