To those who recommended a chisel, let me say, "Thanks". To the rest, let me say, "Thanks". I know there is always more than one way to skin a cat, but the chisel made it seem so easy. After a couple hits using a ball peen hammer against the plug and hittting it with a larger hammer. I used a chisel against the edge to back the plug out. The pic says it all. Take a look!
Here is the pic Picture attached
i do the same thing with broken off bolts if i can get a bite on em
The final drive check plugs on my D6 had the square rounded out and have chisel marks all around where someone used that method the check the oil. I just used my little wire welder to build up the edges of the square hole so a tool won't slip anymore.