Record Macro is

Sub main()

Set swApp = Application.SldWorks

Set Part = swApp.ActiveDoc
Set SelMgr = Part.SelectionManager
boolstatus = Part.Extension.SelectByID2("DetailItem2@Sheet1", "NOTE", 0, 0, 0, False, 0, Nothing, 0)
Part.FontUnits 18
Part.FontUnits 6
End Sub

Question is

Part.FontUnits 18 → Note font size 18

Part.FontUnits 6  →  Note font size 6