How do you turn a unit to a hero in warcraft world editor

its Easy to do actualy. all u need to do is... Create a regin, and make a trigger, make the trigger and make it do. unit enters regin, replace (unit) with (unit) , and if want to delete trigger after you make that, just make a new trigger, and make it say, (unit) exits (regin) delete trigger, and change (this trigger) to whatever the regin is, if you dont know about any triggers, just expirment it a bit, or youtube it, or just ask me for more help.