http://www.wikihow.com/Apologize

This is an article made by wikihow, i think you will get benifit of.

How to Apologize
We all know what an apology is--an expression of remorse or guilt over having done something that is acknowledged to be wrong, and a request for forgiveness. But we also know it can be really hard to swallow our pride and say "I'm sorry." If you have a difficult time making amends for mistakes or repairing the effects of angry words, here's how to keep your dignity while being humble, and invite forgiveness with grace.
[edit] StepsDecide when to apologize. Sometimes immediately after your mistake is best, sometimes not. The sting of a harsh word can be cooled right away with a quick apology, but other offenses might need the other person to cool down before they are willing to even listen to your next sentence. However, the sooner you apologize for your mistake, the more likely it will be viewed as an error in judgment and not a character flaw.

"I'm sorry...I shouldn't have said that."Write your apology down. Construct a letter to the person you're apologizing to, rehearsing what you will say in person. If you don't feel comfortable with writing, then use a voice recorder. Not only will this help you remember what to say when you're face to face with them, but you can also bring the copy with you and hand it to them if you find the apology quite difficult to express. But don't forget that a direct and honest apology is best. Do it face to face, if possible. A phoned, emailed or recorded apology shows a lack of sincerity and effort and should only be a last resort.
Begin the apology by naming the offense and the feelings it may have caused. Be specific about the incident so that they know exactly what you're apologizing for. Make it a point to avoid using the word "but". ("I am sorry, but..." means "I am not sorry.") Validate their feelings or discomfort by acknowledging your transgression's (potential) effects:

"Boss, I'm sorry I'm late again, I know my shift started 10 minutes ago. I hope this doesn't complicate your day."
"Dear, I'm sorry I forgot your birthday - there's no excuse. I hope you don't feel neglected, please let me set this right."

"This is an explanation, not an excuse. There is no excuse."Make amends. Think about what caused you to make the offense. Is it because you're a little too laid back about being on time, or remembering important dates? Is it because you tend to react instantly to certain comments, without pausing to consider an alternative point of view? Is it because you are unhappy with your life, and you unknowingly take it out on others? Find the underlying problem, describe it to the person (as an explanation, not an excuse), and tell them what you intend to do to rectify that problem so that you never repeat this mistake again:

"I snapped at you because I've been so stressed out with work lately, and it's selfish of me to take it out on you. Starting tomorrow, I'm going to cut down my hours to X per week. I really think it'll help me unwind, and help us spend more quality time together."
"I've been distant and cold because I get paranoid that you're going to walk out on me because I don't have a job. But that's a terrible thing to do. Look, here's a list of things I'm going to do to find a job ASAP..."
Express your appreciation for the role they play in your life, emphasizing that you do not want to jeopardize or damage the relationship. This is the time to briefly recount what has created and sustained the bond over time and tell loved ones that they are indeed loved. Describe what your life would be missing without their trust and their company.
Ask if they will give you a chance to make up for what you did wrong. Insist on proving to them that you have learned from your mistake, and that you will take action to change and grow as a result, if they will let you. Make a clear request for forgiveness and wait for their answer. This gives the injured party the well deserved "power" in determining the outcome of the situation.
Be patient. If an apology is not accepted, thank them for hearing you out and leave the door open for if they wish to reconcile later. (E.g. "I understand you're still upset about it, but thanks for giving me the chance to apologize. If you ever change your mind, please give me a call.") If you are lucky enough for your apology to be accepted, avoid the temptation to throw in a few excuses at the end. Instead, have a transition planned out beforehand for what you can do to solidify the clean slate (e.g. "Let's go get some coffee and catch up. It'll be my treat. I miss knowing what you're up to.").
Stick to your word. This is the most important step. A true apology entails a resolution, and you have to carry out your promise in order for the apology to be sincere and complete. Otherwise, your apologies will lose their meaning, and trust may disappear beyond the point of no return. Follow through.

Tips
One on one.If you can, pull the person aside so that you can apologize while you're alone. Not only will this reduce the likelihood of other people influencing the person's decision, but it will also make you a little less nervous. However, if you insulted the person publicly and made him/her lose face, your apology is much more effective if done publicly.
Use relaxed and humble body language. Keeping your arms crossed or pointing fingers will put the other person on the defensive.
One apology will often cause another, either from you for something else you realized you are sorry for, or from the other person because they realize the conflict was mutual. Be prepared to forgive.
A proper apology is always about the injured party. Keep your apology focused on the recipient.

Warnings
Don't be a pushover and apologize for doing things that you should not be sorry for, like being yourself.
Sometimes attempted apologies turn into a rehash of the same argument you wanted to amend. Be very careful not to re-argue any topics or open any old wounds.
Don't be too surprised (or suspicious) if you are forgiven. Take people at their word, just like they took your apology.