The whole sentence is: everyone does it, and not only gentlemen, but also people with both civil and military skills want to do it. Do it constantly.

Everyone (struggles) to do it, and if you persist in doing it, you will become a gentleman. If Wang wants to do this, he can reach the level of Yao and Shun. In the past, if my ancestor Confucius wanted to do this, he could reach the level of king Wen and king Wu. If you keep doing this and don't change, your habits will become the same as you used to, unnatural, and will become natural without coercion.