Try to edit building in wich you want to put heroes like this:
Object edior - Units - (pick race) - (pick building) - Techtree - Units trained (add unit)
For custom spells try:
Object editor - Abilities - Custom abilities - New custom abilitiy
For custom upgrades try:
Object editor - Upgrades - Custom upgrades - New custom upgrade
Object edior - Units - (pick race) - (pick building) - Techtree - Units trained (add unit)
For custom spells try:
Object editor - Abilities - Custom abilities - New custom abilitiy
For custom upgrades try:
Object editor - Upgrades - Custom upgrades - New custom upgrade
