1. Activate the "Hell Mode" by repeatedly clicking on the "A" at the right bottom corner
2. Turn up the heat to max
3. Take off the brake (if you haven`t done that already)
4. Hold the L key to fill the water
5. While still holding the L key, change windows (or tabs idk i forgor what it is called lol)
6. Hover over the game on the taskbar with your mouse to check if the water is slowly disappearing or not. If it isn`t, it worked

It should look something like this

Yeah thats it. The game will be running in the background while the water gets instantly refueled every time it evaporates a little bit, which makes the long process of getting the achievement more bearable since you don`t have to manually refill the water every time it evaporates.

Also yes this is my first guide so it will definitely look bad (+ my english ain´t the best) but I hope I helped ya on getting the achievement.

oh yeah don´t forget to rate this guide n stuff