What rituals do Jews perform to show repentance?

According to Torah, there is a three-step formula for "repentance" (teshuva = returning to G-d by returning to the proper path). Quoting from Mishneh Torah by the Rambam (Maimonides):

"And what is repentance? It is when the sinner abandons his sin, removing it from his thoughts [i.e. he will from now on push out from his mind any idea to do or to imagine doing this sin], and is completely resolved not to do it again.

Consequently, he [verbally] regrets what has happened in the past [i.e. what he thought, said or did] and [verbally] accepts G-d, the Knower of secrets, as his witness that he will never return to such a sin again.

And he needs to confess verbally and state the resolutions that he made in his heart."

“teshuvah” This is represented using two concepts, nicham (to feel regret or sorrow) and shuv (to return)

`When a man or woman wrongs another in any way and so is unfaithful to the Eternal, that person is guilty and must confess the sin he has committed. He must make full restitution for his wrong, add one fifth to it and give it all to the person he has wronged. [Numbers 5:6-7]

30:8 You will repent and obey God, keeping all His commandments, as I prescribe them to you today.

Ve'atah tashuv veshamata bekol Adonay ve'asita et-kol-mitsvotav asher anochi metsavecha hayom.

Deuteronomy 30:8

note the Hebrew word tashuv there

For the person who has sinned to acknowledge the wrongdoing is the first step, then one must regret the wrongdoing and do your best to make amends, lastly, is to turn away from doing the wrong and not do it again.

Jews can do this any time of year as we are always directly accountable to one another and before God for our actions but we have a specific Holy day, the Day of Atonement in which we individually and collectively atone for our sins as a people for sins we commit against God. This is Yom Kippur. Before Yom Kippur we are expected to have sought to make amends as best we can before we seek forgiveness from God.

This essay explains the Torah's notions of sin and repentance and atonement with regard to the Temple sacrificial system and how those precepts are carred on without the Temple. Recall Jews were without a Temple beteween the First and Second Temples and one for sin, and not all Jews lived close enough to the Temple to participate in the sin offerings there, and they too, used Torah precept to atone with God.

There are a few specific customs associated with Yom Kippur including a 25-hour fast beginning before sunset on the evening before Yom Kippur and ending after nightfall on the day of Yom Kippur and the prohibition of certain other activities..and BEFORE Yom Kippur, on Rosh Hashanah, the Jewish New Year, there is also a custom observed by some communities called tashlich ..see the link to learn about it

See this past answers for more:

http://answers.yahoo.com/question/index?qid=201108...

Remember, Yom Kippur atones only for sins between man and G-d, not for sins against another person. To atone for sins against another person, you must first seek reconciliation with that person, righting the wrongs you committed against them if possible. That must all be done before Yom Kippur

Here is more: http://www.jewfaq.org/holiday4.htm

There are no rituals, as such, for repentance; we ask for forgiveness from the person (or G-d, as the case may be) and try not to break that particular commandment again. Yom Kippur, the Day of Atonement, is the time when we formally ask for forgiveness from G-d.

Yom Kippur is the Jewish day of atonement,it is the day when Jews make up for sins

They spin in circles with bibles on there heads!