Scotty,
I was being a little tongue in cheek about the weight of your exciter rotor, but the generator rotor in that BDAX frame 9 beast of yours (formerly) weighted a lot more than 27 tons. Somehow I remember that being the weight of maybe a BDAX 7 series rotor.
amper,
As PHovanian has mentioned, your methodology depends on what it is that you are tying to accomplish in the end. You didn't specify that in your original post.
If your crane access to the generator rotor in the package enclosure is limited, you will have to rail via the use of a platform the rotor to a point where you can lift it with a crane. That would only be necessary if you intended to do some more work on the rotor like remove the end caps, rewind, do bearing journal work, etc.
If your purpose is only to inspect the generator, then you can rail the rotor out on the platform and leave it set there while you accomplish all the tasks.
If you are going to do any detailed work on the rotor then it has to be taken to a clean weather protected place and that will involve the use of a crane at some point.
At this point, it is unclear to us what you are actually trying to accomplish.
rmw