I bought Zvjezdan Misimovic for Derby County in 2012/13 season on a free, so at least I couldn't lose money. Worst signing ever, in 6 months his physical stats dropped so much and had an average rating of 6.2 at the end of the season. He spent the whole next season in the reserves.
Extract it to Documents>Sports Interactive>Football Manager 2010> Editor Data
Then when starting a new game tick Change and on the next screen tick the database you want to use.