Hi,
It would largely depend on the nature of the document and how complex the layout is.
If you open the document in Acrobat (depending on the version, either Standard or Professional) and then go to the File / Export / Word Document command.
This will export it to Word, but the layout will probably not convert exactly as it currently appears in Acrobat.
You will not be able to export the document from within LC Designer itself. So I would recommend converting from Acrobat.
Good luck,
Niall