This procedure works and It's a shame it is not documented.
I guessed it by looking at the interface and then found this post as the only source of information on the topic...
This also explains why each sbus servo comes with a 'mac address' label and 2 extras you can stick somewhere else, so that you can get to them later when the servo is installed in the model.
It's really handy to be able to change something in the programming of a servo once it's installed without having to undo all the wiring...
It would be even better if they could be addressed simply by stating the assigned channel id instead of the bus address, but this complexity I can live with!
One small correction:
d. Input the channel ID I wanted to change along with the servo ID.
Only the servo bus address is necessary, the assigned channel id will be retrieved from the servo memory after recall