Sure you can change the seal with the rotor out. You change it from the outside when you pull the gear box. Just make sure that you really clean out the area first to avoid any contamination.
Crucut thanks for the reply,sounds like your saying I can change the seal when I pull the gear box out,well I do not want to unbolt the gear box I want to change the front seal when the rotor is out .what I want to know is if I can do this from the inside of the rotor cage with the gear box still bolted in placeIJ