Try this steps
1. Obtain the audio file for MOH (.wav or mp3).
2. Drop your audio file into: (depending on ccm version) C:\Program Files\Cisco\MOH\DropMOHAudioSourceFilesHere or
C:Cisco\DropMOHAudioSourceFilesHere
3. CCM > Service > Media Resource > Music On Hold Audio Source MOH Audio Stream Number = chose a number that is not in use, see the left hand screen to see the numbers in use MOH Audio Source File = select the file you want MOH Audio Source Name = use the same name as above Repeat = check
4. CCM > System > Device Pool > select device pool of phones you want to change > "User Hold MOH Audio Source" and "Network Hold MOH Audio Source" = change to file you want