Just put the key in the ignition and unload the steering lock mechanism by rocking the steering wheel back and forth.
Try turning the key at the same time.
It is not uncommon for the ignition cylinder to be all but impossible to turn, if there is a load on the steering lock system.
In order to remove the lock cylinder from the column, you will need to turn the key to the accessory position, then press in on the lock pin that you should be able to see after the plastic steering column covers are removed. It will be facing you as you are sitting in the driver seat. After the lock pin has been pressed in, you will be able to pull the whole lock cylinder out of the steering column.