It might be best to check over on the dedicated MAC forum, the easiest method I know of is to use "ADCENTER" (designcenter or Ctrl+2), although not necessary to have the drawings both open it is probably easiest, have the new drawing as the active tab, then in the 'tree view' of the designcenter open up the 'layers' section for the original drawing and select all the layers you want to transfer to the new drawing, right-click and select 'add'. All the layers and details will be added to the new drawing including descriptions.
The layer state export/import function is for transferring 'layer states' which is something completely different.
