I would like to get my credit score to 0.

Hello,

I am surmising you mean remaining balance that you wish to remove from your Apple Account. Apple provides multiple ways for you to do this.

Read this support article for information about requirements for changing your Apple ID country or region --> Change your Apple ID country or region - Apple Support . In this article (and from Check your Apple Account balance - Apple Support referred to in the article) Apple outlines ways to remove account balance:

+ "Spend any balance remaining on your Apple ID"

If you then find your store credit is less than the cost of a single item and you still have a valid payment method such as a credit card for your old country, you can use the payment method to make up the difference in the cost of an item ( How apps, content, and subscriptions from Apple are billed - Apple Support ). Perhaps buy something such as a music track which you can download and also keep a backup copy. Remember that anything purchased may not be available for re-download in another country but as long as you have your own copy you will always have it.

+ "If you still can't change your country or region, or you have less store credit than the cost of a single item, contact Apple Support" using this link --> https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0998&symptom_id=20198

Apple removes your balance and keeps it.

+ "Check your Apple Account balance" refers you to Check your Apple Account balance - Apple Support

Note the sections "If you have an Apple Account balance that you can't use", and "If you plan to delete your Apple ID or change your country or region"