How to change ICCID code for Iphone XS Max

Hallo dear Apple,

I got a iPhone XS Max from my brother he is in Amarica and i am in Germany, and this phone is Simlock now I buy a rsim but her I need to change ICCID code I have seen to much vedio on youtube but didn't found any right ICCID code, plz help me to make my phone. for example like *5005*7672*00-- and also the last number 88 or 0 but all of them I think expeir.