Ok, tomorrow, try this,
I'm assuming you've got the tube out of the triple clamp.
remove the spring, dump a bunch of kroil, WD40 what ever in the upright fork.
Reassmble the fork, compress the spring with spacers as much as possible, stuff some pvc pipe in there, etc
apply some heat to the bottom of the slider. I'm liking heat guns lately, not too much to burn stuff
hold some ice against the bolt, then use an impact to unscrew.
Loose nut holding the handlebars
He’s one of those who knows that life is just a leap of faith. Spread your arms and hold your breath, always trust your cape. Guy Clark "The Cape"