First of all, you need to have hope that the relationship can be restored. And even better to have a deep conviction that it will do. In addition, each of the partners need to have a strong desire to save the relationship. This is necessary because when building trust again will have to make some number of attempts, and compromises.
If you are the partner who created the problem, the hardest thing for you will solve for yourself that you are worthy of trust. The very first thing you need to do is to apologize, admit their mistakes and ask them to give you the opportunity to correct them. In the case that your partner does not agree to reconcile, or not ready to do it, don't force it and don't rush to change the decision. Give him time to think, to calm down, to make an informed decision.
Over time, when the hurt will be forgotten, or at least will not be as strong, try to repeat the attempt (or several attempts) to reconcile with a partner. Try to talk about your relationship. Explain that you are very important and you want them back. If your reconciliation and you made a promise, stay true to his word. Decide for yourself continue to be honest with this man and stick to your decision no matter what it takes.
If you are the one betrayed and you are left with resentment, you will find it hard to believe your partner, while your feelings will not subside. Take your time to go to reconciliation until the hurt and pain subside, wait time. When you can more calmly accept what happened and talk with a partner, try to listen and understand. Try to imagine yourself in his shoes to understand his motives, and then try to forgive him. This is necessary not only for him but also for you. After all, if you do not forgive the offense, it will sit inside you, poisoning your life. In case you want to restore the relationship, you need to help your partner is to create a real and workable conditions so that it needs to take to achieve confidence.
You have to re-build the relationship so each of you need to compromise. If your conditions seem to be impossible to fulfill the real culprit, will have to go to some sort of compromise. For example, to soften or change too hard (as they sees your partner) requirements. But, if your abuser exaggerates the impossibility to comply with the requirements because he doesn't want something to change in yourself, better concessions not to go, or at least some time to wait.
Never lose your confidence that you will be able to restore your relationship, because it is the one thing that will help you to go through all that trouble. When you get out of relationship issues with a forgiving heart and a lightness in my soul, feeling your loved one, you will get all of this great benefit - will become wiser and more tolerant. If your relationships seem uncertain and shaky, you began to doubt your future, be patient. As for things to recover, it takes time.
A partner who can't trust, will not feel confident and calm. He can't feel loved because he will think that his partner has ulterior motives. He may not be able to close the connection, because it thinks the other is wrong. Lose the trust of the people will become confused, depressed and angry. So, he will not be happy. On the other hand, the man who betrayed him, feels almost the same, if he cares about his partner and wants to save the relationship.
Of course, the relationship will not remain what it was. They will be different, but for better or worse - it is fully depends on the effort the two of you. Most importantly, believe that you will succeed.