You would have to address any immigrations in the Philippines, under Filipino law. We're a U.S. forum.
If you move to a new address, inside the U.S. or out, you would want the SSA to know your address so they can send your checks to you. International mailing often is problematic, so consider instead using direct deposit.
As for paying taxes, just like back home, you put your tax return in an envelope, stick on a stamp, and mail it to the IRS.

