If, "AND ONLY IF" your return has either not been filed yet, OR if it was rejected by the IRS, then the answer to your question is YES.

Under the Personal Info tab scroll down to the Dependents section and elect to EDIT it. You can delete the dependents from there. After you delete them *FINISH* working through the section until you physically click a DONE button. Your changes do not take until you click a DONE button.