not sure if you are living overseas. to my understanding if you are here in canada, you could file the claim (the legal paper he signed to agree the 善養費 payment) to government, and provide supporting saying he missed those payment.
then the government will issue the garnishment to the employer (based on his last income return) and get the employer to deduct such payment from his paycheck and send the money to the claimer.
i never work on case to remit the money to overseas - but could help to check it out and let you know later on...