Ok that makes sense and I figured it was going to be that hard.
Ah **** - surely not? if they're off - can't they be inverted and pumped to drain?One leg is compression and the other is rebound which is somewhat common with upside down forks. They definitely take different amounts of oil. Also you have to completely tear them down to get all of the oil out of them and then put in exactly those two amounts because there's no way to measure with a dip stick like old skool forks you may be use to.
I read through the tear down in the service manual and I think you may need a special tool or two in order to take them down far enough to drain them. It goes without saying that they have to come off of the bike though, unfortunately.