We have a IBM 3583 tape library. You can use the web access which is your http:\\ip address for your library but it is easier just to open the front panel of the tape library, find the correct barcode label and pull the tape out. (When you open the door, the homing picker will go to the bottom and out of your way.)
After I manually removed tapes, I will run an audit, to make sure the library knows the tape is gone