1. Open mission editor, and place a player unit.
2. Preview.
3. Open the debug console and execute the following (It'll display the player's name, set identity, then try to display the player's name again):
[]spawn{hint format ["Local player's name is %1", name player]; sleep 3; player setIdentity "Levine"; hint "Set identity."; sleep 3; hint format ["Local player's name is %1", name player];}