mine are tucked in sort of behind the engine mounts and difficult to get a wrench onto. they were also seized in.
mine were hex pipe plugs, not square, and they tried their best to round off. for some reason i can't remember, i couldn't get a hex socket on it, only a stupid wrench. i finally ended up clamping my best vise grips on the hex to keep it from rounding. when reinstalling, use some teflon tape or teflon liquid to prevent seize.
its worth the effort to remove them. mine puked out scale and rusty dirt.