You can use Promote or Demote to change a provision into another type of provision, depending on its position in hierarchy.
Use Promote to move the provision up the hierarchy, ie: change a sub-paragraph (a) to a paragraph (1)
Uses Demote to move the provision down the hierarchy, ie: A paragraph (1) to a sub-paragraph (a)
The simplest way is to Right Click on the provision you want to change and select Promote or Demote from the menu.