The easiest way to do this is to grab to password for the old Steam branches and switch to Patch 1.22.2
Patch 1.22.2:
Choose to play as the Timurids. The ruler is 67, so it's quick to get to 70.
Go to Speed 5 and wait until your ruler gets to 70.
Don't make your ruler into a general as he will die sooner.
Later patches:
Pick England or Castile.
Go to Speed 5 and wait until your ruler gets to 70.
Don't make your ruler into a general as he will die sooner.
If he dies before 70, restart your game.
This should take 5-10 minutes. One of the easiest achievements in the game.