Skip the Rookie grind. Create a maxed-out Colonel instantly.
While often used for god-mode, the console has legitimate (or semi-legitimate) applications: xcom enemy within dev console full
When successful, pressing the key will bring up a semi-transparent text bar at the top of the screen with a blinking cursor. No confirmation message appears; you’re simply ready to type. Skip the Rookie grind
If you are using Steam directly (without a mod launcher), do this: xcom enemy within dev console full
Because Firaxis disabled the native console in the expansion, you need a mod that re-enables it. The most reliable is the "XCOM Enemy Within Dev Console Enabler" available on Nexus Mods.
Note: If you cannot use Nexus, manually find the XComGame.exe config edit method, but the mod launcher is safer for modern systems.