a. 250K warriors (more would be better)
b. 1 city with Rally Spot Level 9
c. 1 NPC Level 8 - preferably next door or 1 square away
d. 9 heroes to lead the warrior waves - 1 hero must have 150+ attack attribute
e. 30-50 minutes of your time
f. Your title that allows you to have a new city.
g. Good tech levels - Military Tradition, Iron Working, Compass, Medicine (good means 8 or above - since we are hitting an NPC 8)
War Horn, and/or Penicillin
1. Apply War Horn and/or Penicillin - these items help minimize troop loss
2. Un-appoint mayor hero - so you have 9 heroes you can send at a time.
1. 1 Spearhead of 90K warrior lead by your highest attack hero.
Expect 25K to 45K loss - depends on your tech and hero.
2. Send next 8 waves of 20K warrior lead by any hero (level or attack value of hero is not important). Send each wave within 10 sec to 5 minute gaps.
3. As your waves return, medic camp to heal back a percentage of warriors. Upgrade the heros if they receive enough experience points.
4. Send next 9 waves of 20K warrior lead by any hero.
If you are running out of warriors - do not add any other troop type. They do not help bring down the loyalty of the city. Instead use 10K warriors. Whats important here is sending wave after wave to bring loyalty down to 0.
5. Repeat Step 3 and 4 until you get a window asking for you to rename your new city.
Expect to send a total of 40+ waves. I conquered mine in 44 waves.