He was received according to the relevant part of Canon 95 of the Council in Trullo:
And the Manichaeans, and Valentinians and Marcionites and all of similar heresies must give certificates and anathematize each his own heresy, and also Nestorius, Eutyches, Dioscorus, Severus, and the other chiefs of such heresies, and those who think with them, and all the aforesaid heresies; and so they become partakers of the holy Communion.
Currently, the Greek Orthodox and Syrian Orthodox Patriarchates of Antioch more or less do not accept converts from each others' churches. I can't think of a recent example of a non-Chalcedonian clergy member converting to Orthodoxy, but in all cases involving laypeople I'm aware of, it is done by profession of faith.