How do i change my xbox location when the country in the address is greyed out?

I have managed to change my xbox location, but when i try to add in a new payment option, it doesnt let me change my country in the address section. So, i cannot add a new local payment option and cannot make any purchases in the new store.

I saw that you can change the region on your windows computer and that will solve the issue but i use a mac. Please let me know if you have a solution. Thank you

:)