help with ignition tumbler

[american revolution]

Can anyone help me trying to figure this out...i have a 72 blazer with a later model steering column...another member that worked on my car thinks it is a later model steering wheel....pulled up to my house today when i wanted to turn off motor key would not move....took me about 30 minutes to finally turn off vehicle and get the key out and now the ignition will not turn to start vehicle...Been advised that the ignition tumbler might be bad...how do you remove tumbler so that i can replace...here are some pics...At least the car is in my driveway but need to get this going asap so that I can get it in the garage.