Infiltration is an approach/attack on a social system from the bottom upward. This usually means entering the system from outside and advancing through the ranks for personal goals.
If is an attack, it is the aggression of a smaller identity on a larger identity.
How to infiltrate a system?
If you meet the requirements and your personality doesn't deviate much from the collective individual, getting into the system is the easy part.
(If you don't satisfy the requirements, hide your shady history, create yourself a socially malleable personality profile, and acquire/make up the qualifications.)
Once you're in, and if you have no subversive intent, you can advance with clarity while you contribute more to the system than what it contributes to you.
When you reach that limit, you either simply won't get to advance or you will be removed because you're a liability.
To get past that point, you have to intimately familiarize yourself with the structure of the social system and learn the context it resides in.
You have to dismantle the invisibility of the social structure and remantle it so that it is perfectly visible to you, but not to others.
It is time for you to exploit the flaws. (And if it's a system based on power over others, it will have many flaws; you just have to find the right buttons to push.)
The main tools to be used from here on are positive networking, negative networking, and good timing.
Positive networking is the process of obtaining allies who will support your goals, usually by (explicitly or implicitly) offering something in return.
Negative networking is the process of keeping in check those who oppose your goals. This can be achieved by backed up threats to withdrawal of power and status.
Finally, a good sense of timing is required to know when to make allies into foes and vice versa. You won't get anywhere without the fine art of backstabbing!
When you have acquired the necessary power and status most suitable for achieving your goals - it is time to abuse the hell out of the system and squeeze out as much of it for yourself as you can.
(In case you mess up or get outsmarted, make sure you run faster than those who chase you!)