On the customization screen, when you change the name of your soldiers. Remember: Beaglerush must be put in nickname, not in the name or surname unlike the rest.
ATTENTION: Unlock these heroes blocks achievements and trophies of this stored game.
Beaglerush Unlock the grenadier range
Peter Van Doorn XCOM 1 Ranger unlocks
Sid Meier Unlock PSY OP SID MEIER