Wasteland 2: Director's Cut

In the southwestern part of the Hollywood Sewers, where there is a working computer with a large red button behind a breakable wall, in front of the wall there are two locked chests and two Salt Guards.
First, we hack and open these two chests (see the screenshot below).
Then we approach the two guards so that they do not notice you, but start talking to each other (marked in the screenshot with a red dot).
We retreat to a safe place, but so that these two chests are visible (marked in the screenshot with a green dot) and listen to the further conversation of the guards.
A quest appears in the Redondo Beach location.
Let's go to this location.
Pick up a shovel and dig ALL the holes to get this achievement.

Attention, you can miss the trophy! Location Hollywood, sewer (there are several options to get there). You will have to quietly open two chests and listen to what the two soldiers are talking about; if you did everything correctly, check the map; the Redondo Beach location should appear there. After that, you can safely kill them and immediately behind the wall where they stood, make the Pushed The Button trophy.