You will need to download the WebEx player software here: https://www.webex.com/video-recording.html
Here is the direct link to the software you will need:
.arf
Windows: https://welcome.webex.com/client/T33L/nbr2player.msi
Mac: https://welcome.webex.com/client/T33L/mac/intel/webexnbrplayer_intel.dmg
.wrf file
Windows: https://welcome.webex.com/client/T33L/atrecply.msi
Mac: https://welcome.webex.com/client/T33L/mac/intel/webexplayer_intel.dmg