If you already have iTunes installed on your system, you need to use it to transform your M4R ringtone files to MP3.
Ọ bụrụ na i bu n'obi na-agafeta ringtone na ị ebudatara n'ime gị iPhone, ị ga-tọghata MP3 faịlụ ndọtị gị ebudatara ringtone n'ime a M4R faịlụ ndọtị.