You may amend a return in our eServices system to update the tax withheld, wages, and number of employees. Minnesota Withholding Tax is state income tax you as an employer take out of your employees' wages.To complete an enterable form on a computer: Download the Word document to your computer. Open your saved file and select the View tab in the upper left corner. Employees can view and change federal adjustments and state withholding information using Self Service. Those who file a state income tax return in Minnesota which must later be amended do so using a form m1x. See Step By Step Instructions On How To File A MN Tax Amendment. Amended Returns Minnesota does not support electronically filing the amended return Form M1X. Click Submit to complete the order. Record Your Order Number: Write down or print out the Order Number listed on the Order Confirmation page.