This takes place during Mission 11
; and you must choose Allison
over the bank in order to complete this. (If this is not the option you intend to make, create a manual save before the choice and revert back after gaining the achievement).
After choosing to complete M11 instead of M12, you will enter the underground Church of the MachineGod area. Head straight through the bottom area to the other side to find a small basketball court. Pick up a basketball and make a shot or dunk the ball in order to score and unlock the achievement.