Is this an old-type Alfine hub? I recently ordered an Alfine 8 hub as sold today, and one side looks made for an LBS to easily unscrew in order to perform regreasing.
It is quite easy to take out the innards on the Nexus 8 Premium hubs I have, I do this from time to time to grease the two accessible bearings with marine grease to increase the weather resistance and help prevent/reduce oil leaking out.
I don't know if the large plastic cover/seal on the Alfine unscrews or not, the equivalent on the Nexus 8 Premium is a simple press fit. To remove the innards and get at the left hand wheel bearing it is necessary to unscrew the locknut and cone on the left hand side, this should be the same for both Nexus and Alfine 8 speed hubs.
But for regular lubrication it is easier just to inject a small amount of oil through the oil port without removing the wheel from the bike.
