How do you completely delete a unit?

I've been working on a mod and so far to get rid of old units I've just been giving them the no_custom attribute in export_descr_unit, and then removing them from buiding queues in export_descr_buildings. This works fine, but the game has a 500 unit limit, and these units are still taking up space, and I'm going to run out of space soon if I don't delete these unused units. Does anyone know how to completely delete a unit?

Delete them from

Descr_model_battle
Export_descr_unit
Export_descr_unit_enums

and
export_units ( in the 'text' folder )

That, plus making sure you have removed them from the building unit lists and made sure there are no units of this type available to start with in the campaign.

check also descr_rebel_factions and descr_mercenaries.~;)