1. Make a sandbox game with the following settings:
Economic and political Difficulty: very easy
Starting cash: unlimited
Starting Population: 100, preferably
Stating Era: Modern Times
Whatever map you want.
Victory Goals: none
Disaster chance: none
2. Pause as soon as the game loads in. sign the tax cut and extra rations edicts, as well as and any others that say they raise happiness. Slap down clinics, police stations, cathedrals, and newspapers. Insta build them, set the budget to max, and hire overseas workers for the college educated positions.
Happiness should rise pretty quickly and the achievement should pop. If it doesn't, go to the happiness section of the journal to see what needs improving