how can I edit jockey names like put some new apprentices in the game like Marquand ,hardie ,sheppard all them lads

Navigate to:
C:\Program Files (x86)\Starters Orders 6\data

The numbered folders in there contain data for each region (1 is UK, 2 is USA, not 100% on the others). Inside the one you want to edit the data for will be a file named "_jockeys.dat" which you can open and edit with Notepad/Wordpad or a similar program. Just edit the names in there and start a new game to see your new jockeys in the game.