Adding Ai Bots in MA is very easy! Just host a game, click on the "Add Ai Bots" button on the top right of the screen and then choose a hero to spawn.

It is very importan thou: That side line bots must be spawned at the river towers while the mid bot must be spawned at its side's fountain. Also Good Bots must be spawned on the Good Side and remember to "Choose Side" to Evil when spawing bots for the Evil Side.

Also, max of 5 bots per team, otherwise the client becomes unstable.