How do we pull down strongholds? Expounded

Now I, Paul, myself am pleading with you by the meekness and gentleness of Christ—who in presence am lowly among you, but being absent am bold toward you.
2 But I beg you that when I am present I may not be bold with that confidence by which I intend to be bold against some, who think of us as if we walked according to the flesh.
3 For though we walk in the flesh, we do not war according to the flesh.
4 For the weapons of our warfare are not carnal but mighty in God for pulling down strongholds,
5 casting down arguments and every high thing that exalts itself against the knowledge of God, bringing every thought into captivity to the obedience of Christ,
6 and being ready to punish all disobedience when your obedience is fulfilled.