Shaikh Bin Baaz [rahimahullaah] said:
The conditions [to be fulfilled in order for repentance to be accepted are] three:  To be regretful and remorseful regarding the past (acts of disobedience you committed);  To renounce and abandon the sins – the big and small (of them);  To have a firm resolve [or determination] not to return to it [i.e. not to commit them again]. If you owe the people their rights- wealth or [you committed offences related to blood-shed, murder or causing injury etc] or violating their honour, then their rights must be given back to them. This is a fourth affair related to a complete repentance. It is incumbent upon you to give the people the rights they are owed. If the affair is related to retribution, then retribution is established [i.e. by the state], unless they [i.e. the people] permit that you give blood money; if related to wealth, you give them back their wealth, unless they forgive; if related to their honour and you did backbite them, you should seek their forgiveness; but if seeking their forgiveness will lead to evil, then there is no hindrance in refraining from [informing them that you did backbite them and that you seek their forgiveness]; rather you should supplicate for them and seek Allaah’s forgiveness for them, and mention the good you know about them in the same place you did mention them with evil. This will be expiation for (that sin of backbiting). And it is incumbent upon you to proceed –without delay- towards repentance before death, and then exercise patience and be truthful.