repicking heroes

im making a AOS map where you choose from 8 hereos and pick one. When you do, one gets created. If someone doesnt like that hero i want them to be ablet o type -repick and remove that hero from the game and create the wisp (unit that chooses heroes) to be created. I get the wisp to be created but the created hero doesnt get removed. Can someone tell me the full trigger stuff i need to do this? thx

If players only control 1 unit all the time, use pick all units owned by triggering player and unit - remove. Other wise when a unit selects a hero set that unit to a unit varible.