Q: how to change apple store

You are in the country that you want to change to ? If not then you cannot use that store, you have to be in a country to use its store.

If you are then log into your country, change the country/region on it, and enter your new country's billing details : Change your iTunes Store country or region - Apple Support

See the following instructions: Change your iTunes Store country or region - Apple Support

You are likely to receive a temporary store holding charge to check that the card details that you enter are correct and that the card is valid - your card issuer should remove the 'charge' within a few days, and (if the card is accepted by iTunes) you should then get the 'none' option and be able to remove the card.

The charge is only temporary (and will only be $1 or approximate local equivalent), your card issuer will remove it from your card within a few days or so. After you've entered the card, and if it's accepted by iTunes, you should get the 'none' option and be able to remove the card