Place the cursor where you want the Roman numeral to appear
Go to the Insert tab
Click Page Number if you want Roman numerals in page numbering
Choose the page number location and style
Open the page number format options
Select Roman numerals in the Number format list
Click OK
If you want to type Roman numerals manually, use I, II, III, IV, V, VI, VII, VIII, IX, X
Use uppercase Roman numerals for standard formatting
Use lowercase Roman numerals if required by your document style
Switch to the desired font and size if needed
Save the document