(Yusuf Ali) Men are the protectors and maintainers of women, because Allah has given the one more (strength) than the other, and because they support them from their means. Therefore the righteous women are devoutly obedient, and guard in (the husband’s) absence what Allah would have them guard. As to those women on whose part ye fear disloyalty and ill-conduct, admonish them (first), (Next), refuse to share their beds, (And last) beat them (lightly); but if they return to obedience, seek not against them Means (of annoyance): For Allah is Most High, Great (above you all).
(Shakir) Men are the maintainers of women because Allah has made some of them to excel others and because they spend out of their property; the good women are therefore obedient, guarding the unseen as Allah has guarded; and (as to) those on whose part you fear desertion, admonish them, and leave them alone in the sleeping-places and beat them; then if they obey you, do not seek a way against them; surely Allah is High, Great.
So as the last result and lightly.
and where does it say about forcing them to have sex with u.
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2020-6-09 -- Updating my answer based on new learnings (as the internet is "forever").
The initial quote I took here is one English interpretation of the Quran taken by Yusuf for this passage, whether it means to say "lightly" is something that will need to be studied in Arabic to get the correct understanding.
However, the point here is that the Quran is giving us some guidelines on how best to approach a situation (maybe a constant argument or misbehavior, similar to what you may find with children) with your wife after first having admonished them, then refused the bed, and the final leading the "beating" (how hard is something which is not specified, so it could depend on the situation). One thing to note, though, to "beat" is the final action that the Husband might try. Remember this is not the first thing that is said to be done. One must first use logic and reason to get an understanding of why this is happening to get an understanding and then take the next appropriate steps. Remember this is a relationship between man and wife. The man is not inclined to be violent in any manner but if the wife has taken it to that stage, then that situation is between the man and wife and no one else. Unjust and unnecessary violence against women or anyone is forbidden and should never be taken! With correct dialog, anything can be solved (one must make the effort).
Just like if you have a child who constantly misbehaves, and they don't learn, and there is no logical reason for this misbehavior, then the parent has full right to take any action as they please. If they see fit that they must hit the child after constantly reminding the child of there behavior then that is the punishment.
Remember, the Quran mentioned that this is the final resort. It doesn't say this is the only resort, and that these are the only 3 methods to solve marriage issues. The Quran is giving you guidelines, which our Creator sees fit the best possible methods to handle these types of situations. Solving problems through reason and logic (Admonish) is the best method to avoid violence. Plus when you use reason and logic, you are using the creative part of your brain to solve a problem.