I have the ignition switch off and the replacement ignition lock, but I can't get the old ignition lock off....any suggestions?

to get the cylinder out:
you need to drill a hole in the precise spot. look at the new cylinder you have there is an indent about 1cm from the part that wraps arround the column. you need to drill a small 1/4'' hole on the top side and it will release the cylinder to pull out

the actual bracket itsself that wraps wrround the coulmn you need to press off with a bearing puller.

Thanks for your help. With your info and some other info from Windy Gregory, I was able to drill the hole close enough to get the cylinder lock out and replace it with a new one.