Slitherine

I want to create a second wave of Orks but I can't see how I set the units as reinforcements.
I've looked at scenario 12 but can't find how the space marines are set up.

A short "how to":

1st way:
You have to place units on the map.
After that you open the unit detailed window in the editor. I dont know, Ctrl-click or Shift click on the unit.
Add a trigger. You can choose the condition.
If the trigger is TRUE, the unit appears on the map.

2nd way:
Place units on the map.
open detailed window. Choose the orders (hold position?).
Make a zone where the units are. Add a trigger in the scenario options to set the units in the zone to attacker.
The units are allways on the map, but only attacks if the condition is TRUE.

Ah, 1st way is what I want, thanks. I want them to actually arrive on a certain turn.
Bit cumbersome though, having to do that for every unit. Would have been nice to be able to do this to all units in a particular zone, via the params.