Advised on FAA Repair Station outside USA

Dear all,
A friend of mine has an avionic repair shop outside USA. He dosn't
have FAA repair station certificate as yet but look forward to apply
one soon. He asking me if it's possible to buy broken radio in US,
send back to his shop for repair service and then send back to US for
certified? Also how hard is it to get repair station certificate
outside US. Who should he talking for additional information.

Any advised will be greatly appreciated.

Paul