So stuck differential plug, or probably seized, wow.
over a few weeks i tried
heating up the nut, this was the scariest option for me, cuz i'm right underneath the car.
penetrating oils
1. pb blaster
2. liquid wrench
3. wd40
4. wax + heat (heat the nut and hold a candle next to it, the threads will "suck" in the wax)
5. ppl swore by brake fluid + atf fluid 50/50 mix
yes i have a real breaker bar (not just a ratcheting wrench), and i have a long cheater extension for it too (just a lead pipe that fit)
Then i tried having the breaker bar on the plug and putting the jack underneath it to push it counter clockwise, this is ultimately what "stripped" the plug.
So w/ the plug stripped i had 3 options left,
1. weld a nut onto the stripped plug, usually ppl say the intense heat from welding is also what breaks the plug, however i have no idea how to weld or anything.
2. drill it out with one of those extractor sets
3. chisel it out
I went with option 3, i chisel'd out a slot, then with a screw driver once i made a nice enough slot and just kept on hammering away. this still wasn't doing much, next i tried to use a "cold chisel" instead of a screw driver where the screw driver has a molded plastic handle and maybe absorbing the force and a cold chisel is just a long piece of iron.
ultimately what i believe worked was the "shock" method heating up the plug for an uncomfortable 2mins then putting a huge ass ice cube right on it. (my ice cubes are 1in in size) then using the cold chisel with tappy taps instead of hulk smash, after a min it moved.