How does one repent from kufr or shirk?

[Aishath]

Asalaamu alaykum,

Whenever you get these kinds of thoughts think to yourself "shaythan is just trying to mess with my head and confuse me and i won't let him" and then repeat the following: "A'udhu billaahi minashaythaanirajeem", Also: "La hawla Walaa Quwatha illah billah hil 'aliyyil adheem".

Brother Hamza, would you be able to please send me the Arabic writings of these Dua's (the second one), since I find it easier to read it when written in Arabic. I am more sure of the pronunciations then.

Thank you. Insha Allah, may Allah bless you. Ameen.