The principalities and powers cannot be referring to human rulers or kings. It is referring to the spiritual forces of darkness, the evil powers or in simple terms demons.
First let's look at the translation. While NET speaks of "disarming the rulers and authorities," NABRE says "principalities and the powers." So do KJV and NIV. NET's translation makes the question more difficult. If we are actually dealing with spiritual powers rather than political ones, the answer is clearer: Jesus' death atoned for sins under the Law, thus removing its authority to punish ...
We wrestle against principalities, against powers, against the rulers of the darkness of this age, against spiritual hosts of wickedness in the heavenly places.” Ephesians 6:12 NKJV Who...
For I am persuaded that neither death nor life, nor angels nor principalities nor powers, nor things present nor things to come, nor height nor depth, nor any other created thing, shall be able to separate us from the love of God which is in Christ Jesus our Lord. St Paul travelled extensively - both by land and by the seas- to witness Christ.
10 To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God, 11 According to the eternal purpose which he purposed in Christ Jesus our Lord: 12 In whom we have boldness and access with confidence by the faith of him. (Eph. 3:4-12, KJV)
New King James Version Having disarmed principalities and powers, He made a public spectacle of them, triumphing over them in it. Which is to be prefered in him or in it? This question was inspired by this other question: When did Jesus disarm rulers and authorities?