To execute a turn, all the models remain in place but are turned through 90° or 180° to face their side or rear. For every 90° it turns, a unit uses a quarter of its Movement characteristic.
When a unit turns, all models in complete ranks simply turn on the spot. Any models in an incomplete rear rank are moved to the rear of the new formation.
When a unit is turned to face its side or rear, any Command models it contains are automatically placed into the new front rank. If there is not enough space in the front rank, such models are placed in the second rank.