As everyone knows, lying is one of the great and major sins. Let's say, at some point, a person lied a small lie. How can he repent? Does he need to tell whom he lied to the truth? Or is it enough to do istighfar (repent)?
In the name of Allah, the Most Gracious, the Most Merciful
As you all probably know, lie is considered as a haram (forbidden) deed. As you pointed out regarding Tu’bah, the best way is repentance concerning that to make it up for the your previous mistakes.
As a brief answer for your constructive question as you asked
How can he repent? Does he need to tell whom he lied to the truth? Or is it enough to do istighfar?
It is declared that in regard to compensate for the sins such as lie, repenting is sufficient (by doing its steps (the steps of a real repentance). Of course there are some items who he should pay attention to, such as:
For instance, in case of accusing someone …, he/she ought to remove the negative accuse of that in front of the persons who he has lied about. (In order to remove its unreal… from the mind of others.)
He ought to confess to his/her lie in the cases which he has lied as a witness, in order to make up for his mistake (to regain the right of the person who was trampled by his lie speech). And some more related explanations that I endeavored to indicate some of them briefly.
Based on your question concerning telling a small lie, the best way is repentance. In the meanwhile, you ought to compensate what you have trampled by telling that lie (as much as possible) by different ways such as informing the persons who … or even compensate or make up for the financial disadvantage if… / Besides, to the best of my knowledge, seemingly, you should not confess to that small lie IF confessing to that make you a more remarkable difficulty. (But as I stated, besides the repentance you should make up for the financial disadvantages or the items which led to discredit…
And Allah Know Best.