Filestream with entity framework

Hi, I'm developing a desktop application using entity framework 6 and sql to store different type of documents like Pdf, Word, Excel Image, etc.., I managed to activate Filestream with my SQL database and saved successfully the data as byte[] but now I need a way to retrieve it using also entity frame work so when I double click on file name in datagridview, it will open by default app in computer. help me please!.