That stud looks like it had been stretched previously, there is still slight 'necking' showing in picture.
Remove fork top nut and get the area around stud real hot, it may be Loctited in. I think temp needs to be minimum of 230f ?
If it's hot enough, a vice grip will loosen it up, you shouldn't need to re-drill anything but a good 8x1.25 tap should be used to clean threads
A good stud extractor is EXPENSIVE, the only one worth a damn is the Snap-On CG500, I paid almost $110.00 for mine in 2005~6 , wish I'd seen one 30 yrs ago would have saved me a lot of grief on various motors