How would I go about vacating a felony so I can go for a nursing job?

There is no such thing as "vacating" a felony. If you have been convicted of a felony, you may be able to get a pardon or get it expunged. You would need to hire a lawyer to try and get this done.

But its not easy to get done. Generally a good deal of time would need to have past during which you have demonstrated rehabilitation.

In most cases they will want 8 plus years to have passed with you getting into no trouble, perhaps increasing education, working a steady job and so on.

You will have to hire an attorney to make the motion to the court.