After selecting the "Setting" option at the hangar and the "Auto Save/Password" option, activate the following cheats by entering the corresponding codes:

CHEAT FUNCTION - PASSWORD
All Zentradi Arms EX mission - Enter EHIAR as a password.
Do You Remember Famitsu? EX mission - LAMGV as a password.
Generation Drive EX mission - Enter KSALE as a password.
Super Dimension Gladiators Dengeki EX mission - Enter IGYSU as a password.

Unlock the following EX missions by performing the corresponding tasks:

EX MISSION - HOW TO UNLOCK
Macross 7 EX mission - Get an "S" or better rank in Maiden's Gerek (mission 7) and Nightmare Assault (mission 15).
Macross Frontier EX mission - Get an "S" or better rank in Miss Macross (mission 8) and Friendly Fire (mission 10).
Macross+ EX mission - Get an "S" or better rank in Dog Fight (mission 12) and Song Of Angel (final mission).
Super Dimension Fortress Macross EX mission - Get an "S" or better rank in Longest Birthday (mission 9) and Pine Salad (mission 15).