First thing I would try is a 'Hansen' type extractor (aka spline screw extractor) hammered on there and that plug should back out. (don't buy a cheap tool otherwise you'll be faced with extracting the tool bit too)
If that fails then:
Is there enough to get a punch on the edge to get it turning? Not driving toward the threads of course.
This.
If you have never done it before, watch a few videos on the technique. Should have plenty of access and that plug looks large enough that you should be able to avoid the extreme edge and thus not bugger up the threads on the axle side. Air hammer with an appropriate bit would be my choice but the manual method with patience work too.