Recently I had to reset the admin password for an array that was not in production. The problem was it would give me the nmessage "Waiting for GiveBack" but since I didn't know the admin password I couldn't give the command on the active controller. So It was a little challenging because of the clustering.
This is how I ended up doing it in the end.
1. Connect a serial cable to one controller 1 and verify it was prompting for login prompt.
2. Power off both Power supplies
3. Power on one (or both Power supplies)
4. When Controller 1 says "Press Control C" to stop boot process (Or something like that.) then Press Control-C. This will take you to the "Loader-A" menu. (This is needed because you have to pause the bootup of this controller. Otherwise when you chose option 3 on Controller2, Controller 1 will be finished booting and controller 2 will hang at "Waiting for Giveback")
5. Now move your serial cable to the other Controller. (You have to do this quickly)
6. Wait until this controller says Press Control-C for Boot menu. -> then press Control-C
7. Then chose option 3 for "reset Password"
8. It will then think for a while and then give you an option to reset the password.
9. Then it wil finish booting this controller and prompt for login. Login with your new password.
Then move your serail cable back to controller 1. At the "Loader-A" prompt type autoboot. It will come up to a screen "waiting for GiveBack" At this point on Controller 2 you can issue the give back command.
FYI: The admin password is synced to all controlers in the cluster so you do NOT need to change it on both controllers.