Posted by chriscase on Saturday, May 21, 2005 at 11:04AM :
Step one should be to remove the freeze plug in the head, near the rear, just over the water temp sender. Then, unscrew the gland nut thing that holds the bulb in, Now you can cautiously pry the bulb out with a screwdriver HOPEFULY without flexing/yanking on the line and breaking it. I forgot when I did mine, had to rebuild the sender. New freeze plug cost $2, sacrificial gauge cost me $25.