Freeze Plug Replacement Motor in Car

What's the best method for replacing a freeze Plug without pulling the motor? My 68 Valiant just chucked one out the the passenger side bank while I was trying to pass someone. I believe it's the middle plug, but I haven't gotten a great look at it yet, since the motor's still hot and I'm waiting for a tow. Any tips and tricks to use to get the new plug in?