Hmm well, i actually found a 6 sided size 17.

Its like a tube with a hole in the middle.
So i gently hammered it onto the plug, (so it was on nice and tight)

I put a LONG screw driver in the hole and pulled, but it always falls off, like 1 edge is round ?? I cant use my other hand to hold it (but it doesnt feel like that wud help, it always just slips off one edge (not a round corner, the edge?) because its too low. But its not a good idea to jack it up and try remove the plug, is it ?