You can't do this with any of the thumb images. these are very low res images used in the preview.
Are you importing the iSTAR data into Cyclone using the iSTAR/Colourcloud import? If so then there's nothing you can do at all as you have no access to the source images or panorama with ColourCloud.
If on the other hand you are taking the processed spherical panorama from Immersive Studio and importing that into Cylcone via cube faces, then you could edit the people from the panorama using something like the new panorama edit feature in Photoshop CC, but it's going to be quite an operator intensive task I'm afraid.