First you need to go through all 5 robberies - get some platinum medals, then you can easily replay the first robbery. The first robbery the most simple and quick time and only need one partner can take place even with randomness.
Robbery Fleeca. (Pt 3)
1.Exploration - Platinum gets the driver.
2.Kuruma - Platinum gets the driver.
3.Bank - Platinum gets the driver.
After completion of the robbery, it will not be available for some time. Goes completely out of the game in the console menu and then run the game, the first robbery will again be available.