You mean you want to recreate your word documents from PDF? I think the best way is to find the original files if possible. As you have used MAC OS, I would give you some advice as I also a Mac user.
(1)use Adobe Acrobat. It can run on MAC OS and you can save PDF as your word 2008 for specific use. The cons is that it is too expensive and I am not sure the free trial would help you. Acrobat
(2)use Open Office. Open Office can help you save PDF as word. It is open resource. As you use Office 2008. I am not sure all the formats and elements would be preserved well. You need to check it out yourself. Open Office
(3)Use AnyBizSoft PDF to Word for Mac, which is an application designed for Mac users. I think it could definitely meet your needs. It is not free but very cheap compared with Acrobat. PDF to Word for Mac
Hope my suggestion would help you.