Login to your Paylocity account on a desktop computer or laptop

Navigate to HR & Payroll from the left hand side drop-down menu

Hover over "Employees" on the top menu, then select "Employee Payroll File" from the drop-down menu

Select Payroll Setup, and then select Taxes

Click on the blue "FITW - Federal Income Tax"

Once you have reached this page, you can make any edits/updates needed. From there, you simply save changes by selecting "Save & Return"