EMERGENCY! My Apple ID isn't valid for a specific region

I used to live in Chile but then I moved to Asia. So my apple id was made back in Chile, and im trying to download os x el capitan but i cant because it isnt valid in the country im currently in. How do i get capitan, how do i change the region of my account?

I need to fix this tonight, because tomorrow i will need to have a fully updated macbook for school!

please help, thank you loads!