You can change you default address and can make your latest address as default address.
Please follow the simple instructions.
1. login to your MY ACCOUNT
2. Go to Address book on the left panel
3. click on ADD NEW ADRESS on the top right corner of the page
4. Update your address
5. Check the box which says "Use as my default billing address" and "Use as my default shipping address" whichever you want.
6. Click on "Save Address" and you are done.
Your latest address will be your default billing and/or default shipping address henceforth.
If you wish you can delete those addresses which you do not require any longer.