At some point the solenoid died (or some other electrical component). So to start it, you'd have to reach under the car with a screwdriver (or some other piece of metal, but I kept a screwdriver in the car for this purpose), and short out across two terminals.
You then had 10-20 seconds to get out from under the car, into the driver's seat, and turn the key. As a practiced manouver, it was pretty quick.
Now that I've finally got a reliable car and the money for the $20 solenoid we have a saying about cars in general:
Used to have the time but no money, now got the money but no time.
Contemporary GM solenoids were integrated into the starter motor and were a real pain to get to. Certainly not impossible to do the screwdriver trick but far less convenient with needing to crawl around on the ground and all. Being located right next to the exhaust headers also meant they were easily susceptible to heat soak problems which would cause a failure to activate - especially if you have a hot-running high performance engine. It was actually a pretty common and easy mod on those GMs to use a Ford solenoid and bypass the one on the starter motor.