have been having trouble with the tumbler/switch assembly. have not removed key in probably a couple of years. if someone other than i removes the key, usual result is my playing with the bugger for minutes trying to get the key to turn. today, as per great instructions provided by 'diesel giant' and others, i removed the tumbler. it works fine. my problem lies in the 'switch' assembly. please correct me if i am in error. but seems to me if i depress the little 'thingie' at the bottom - where the tumbler mates with the switch assembly, i can rotate same with a screw driver. question. what prevents me from sticking something in there to depress permanently the tab? sorry if this is confusing. i tried my best to explain. thank you.