To learn the safe combination, remain in the Lidl Heist (end of the second stage) without stealing anything. To do this easily, progress until the heist then do not make any selection when offered the choice of going loud or being in stealth. It does not matter if the Lidl manager tells you the safe combination or not; just remain at that screen with the loud or stealth choices.
Easy "Beyond the Possible" achievement
Select level 1, as it is the easiest to complete. Some areas may require a few attempts to learn. At the harvester part, travel in circles to avoid the rat. If you run over the rat and return to the game it will crash. Once at the heist, choose whatever you feel comfortable with. If you die, the game will resume at the start of the heist.
Easy "GaGa" achievement
While playing David on the "London" map, cycle through all the radio stations available.
Easy "Know Your Enemy" achievement
Complete the game and watch the credits.
Easy "Paradox" achievement
Note: You may change your system date to make this easier. On a Saturday at 10:04 p.m., crash into the clock tower on level 3, "London".
Easy "Practice Makes Perfect" achievement
Complete London level without dying. To do this easily, play in windowed mode. If you die, immediately close the game by clicking the "X" icon in the top right corner. Run game again to resume the level without your death being recorded. Continue until after after helicopter part. You do not actually have to do the heist.
Easy "Spud-U-Like" achievement
While playing as Darren at the Lidl Car Park, do not kill rapper until "Spud-U-Like" is earned.