Hope your "legal" document is not as vague as the question.
fruhulda has asked you twice where you want the roman numerals. In page numbers, or lists, or what.
If you want page numbers:
Menu > Insert > Page Number > right click on the number and change it to roman numerals
If you want to list the points using roman numerals:
Select the List button on the Toolbar and chosse Harvard. You can further refine the numbering types for each level of a list in:
Inspector > Text > List > Bullets and Numbering > Numbers > chosewhat you want for each level