No, I don't think there is an easy way to change the inode number manually. Seems strange that it maintains the inode number across multiple disks.... no idea how/why it does that. Here are a couple of other options.
It isn't a Single Instance Store even at the inode level, so if you make a copy of the file on the same disk, the copy should have a completely different inode number. If so, then you can delete the first file and let UpdateMedia rescan the copy. Failing that, if you have a Windows machine somewhere on your network, move the file there and then back again.... there is no way I can think of that Linux would be able to maintain the inode number in this scenario (unless it is somehow generating the inode number by hashing the filename or contents, but that is just ridiculous!)