On Main Menu you will find the "Game Modes" option, select "Arena Mode" to enter the survival. This is set on HARD by default, after each round they will let you to choose between 2 weapons and 3 abilities, which you can upgrade before each round if the options is granted.
This isn't as hard as it sound, if you die you will not restart the survival, you will start the round again. So, you only need to be patient.
By round 9 you'll maybe get the 50000 points you need for the achievement, even if you die over and over.
Theachievement unlocks after you finish all rounds.