Preparations
Getting an administrator (senator, chief, chieftain):
In order to get an administrator you need to research him in your academy level 20 (you also need a rally point level 5 as Teuton or level 10 as Gaul and Roman). After this you can build him in your palace or residence as long as you didn't build settlers already.
The Senator (Roman) is very eloquent and persuasive, he can lower the loyalty by 20% to 30% each time.
The Chief (Teuton) is especially cheap, he can lower the loyalty by 20 to 25%.
The Chieftain (Gauls) is 20% faster than the others, he can lower the loyalty by 20 to 25%.
The values for the administrators are written down for the optimum case, due to the moralebonus they will most likely not be like this when taking over a village.
After the loyalty reached 0% the administrator who did this will vanish and the troops guarding him will stay in the village as defence.
Attacking
Conquerable villages:
Only villages that are not the capital of a player can be conquered, regardlessly where the palace is.
Hint: You can only conquer a village when the residence or palace is destroyed, you have enough culture points and the village you are attacking is not the capital.
Attackwaves:
The conquering should consist of waves because sending everything in only one attack is very foolish. The first wave should be the one with the "cleaner" which kills all defenders, afterwards the catapults destroying the residence or palace followed by the administrators.
Assuming that you own 3000 Imperians, 60 catapults and 2 Senators:
1. 2700 Imperians as "cleaner", should be send as normal attack to avoid trouble.
2. 150 Imperians and the catapults to destroy the residence or palace, normal attack or the catapults won't shoot!
3. 150 Imperians and the Senators, normal attack or the Senator won't do his job.
Repeat step 1. and 3. as often as needed and check whether the victim rebuilt his residence or palace!
Defending
After the attacks:
Rebuild the residence or palace as fast as possible to rise the loyalty again and put some decent defenders including some spies into the village.