1. you want to go into the editor that came with the game
2. then you need to go onto the players tab
3. search for the first player you want
4. change his contract so he plays for the club you want to control
5. repeat steps 3 and 4 untill you've moved all the players you want
6. save the file with a suitable name
7. start up fm and select the change box at the bottom of the screen
8. tick your database with the players in your team
9. then hit the continue button and you should be able to play with these players at your club
10. just remember you would have to start a new game for the changes to take effect and that they won't take effect in a game previously started.