I think you will need to take it out to get the RFID ring off. I would at least take out the dash and use the key to unlock the retaining pin first if you can. Then you won't have to drill it out. The ring cable should be long enough to let you twist the ignition past the retaining pin. Or if possible, you can take the FOB off the key while it's in the ignition? Then you wouldn't have to take the key out at all until you finish.

The good news is if you really ordered the new one and you want to take the cylinder off (which requires the key as you mention), you can open the panel on the side of your old ignition and pull out the pin/spring to get the to turn and take off the cylinder. There is no worry and don't listen to people who had to cut off their cylinder and order a new one.

At that point, you can decide to reinstall your old ignition with the permanent fix or reinstall a new one that will leave you stranded some random later day.