If the two documents use different lists, there is no simple way to change the formatting. You can copy formatting (including numbering) by placing the insertion point in one list item and pressing Ctrl+Shift+C. Then click in the paragraph where you want to change the formatting and press Ctrl+Shift+V to paste formatting.

On the other hand, if you are just trying to change list indentation, click in the first list item and then click Home tab | Multilevel List | Define New Multilevel List (yes, the command is misleading, because it applies even when you want to modify an existing list). In the dialog box, change the indentation for each list level.

__________________
Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional