The same way anyone starts negotiating with anyone: open a dialogue and exchange demands, and then work to make concessions and compromises. They won’t do that, though, because then the infinite money spigot from the US will shut off because America doesn’t want this war to ever end.
Yes. That’s literally how peace negotiations work. The alternative, winning the war, precludes the necessity of peace negotiations. All negotiations in the history of negotiations are negotiations between aggressor and agressee.