You would have to switch the order in the "Personal Info" section, then go through all the tax forms to see that everything is allocated to the proper person.
Depending on how complicated the return is, you might clear and start over.
If the names are reversed from the prior year, your return might be rejected by the IRS E-file system.
HERE is a link that explains how to clear your return.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"