I am trying to change the ignition pickup

If you have the distributor out of the vehicle, there is a pin that goes through the drive gear. drive it out with a small drift or if you don't have one you can use an exotic tool such as a ten penny nail that has been blunted and ground down to size. Once the pin is out, slide the gear and any shims off the shaft and keep them in order fro replacement. Once the gear has been removed the shaft slides right out of housing. You can re-use the roll pin from the gear so don't loose it! Make sure you mark the rotor position using a reference mark on the block or you will mess with ignition timing. Rotor must point to the mark exactly after replacing. Sometimes you will need to use a long screwdriver to turn the oil pump shaft to allow the dist to fully engage.