Hello daria275,
this is a user-to-user community, so nobody here can access your Apple Account or remove the remaining balance.
If you want to change the country or region of your Apple Account, the remaining Apple Account balance normally has to be spent first. If the balance is too small to buy anything, you cannot clear it yourself in Settings. In that case, Apple says to contact Apple Support.
You can check the balance first in the App Store, then contact Apple Support for the country or region your Apple Account is currently set to.
Apple explains it here:
Change your Apple Account country or region - Apple Support
So in short: spend the balance if possible; if it is too small to spend, only Apple Support can help remove it.