Hello there,
I've never heard of an ignition barrel being fitted upside down, have you got any photos to show your issue ?
To be honest I'd be careful as some models can have the immobilizer ring attached to barrel/switch, so you don't want to just force it out.
Using a good LED torch are you able to see down inside the small hole, where the pin goes in ?
Or can you gain access or see better from the back of the ignition lock area with a small mirror ?
I've heard of people having to drill a small hole in the side of the ignition barrel assembly, to gain access to the locking tab that the pin just can't reach, on some VAG vehicles.
I've found this online of a
guide to remove & fit ignition barrel.
Si