On the fill plug- talk to Jerry at Burt Toyota and get an allen plug. You'll never strip it again. Use 'em all over the 4Runner, for drain and fill, tranny and diff. Wunnerful. I think they came stock on a Corolla or something.
On removing the old one: weld on a nut. Really. WFLLT.
Heb Dduw, heb ddim; Duw a digon
I'm that gun-totin', farm-raised, evangelical, pro-environment, OHV ridin'/drivin', Southern civil rights pro-labor Liberal yo' momma told you couldn't possibly exist.