See if you can get on it with pliers or something like that (I have a piece of pipe with a U shaped notch cut in the end that just slips over the end of the pin and traps the fat part inside the pipe). Pull it out smartly and the retaining clip will pop out and so will the pin. You will not be able to get the clip back in with the engine accessories (injection pump, vacuum pump, etc) in place. The paint ridge inside the timing pin bore seems to hold it well enough.