you can try putting downward pressure on it to pull it out as you spin it,grip of some sort but.
Use your imagination lol
unless you have a tap and die set or a helicoil your screwed literally.
i had a yamaha shop fix a drain plug for me 1 time for $50 bucks on old cr125
i was lacking the tools and in a hurry
even if you get it off you need to fix thread's on the case or at least inspect them?
they sell rubber plugs at autostores/ hardware stores but that is risky and ghetto temporarily fix