Press Triangle to get into the menu, select 'Skills' then select anyone. Then Select Skill. Go down to 'Level 4', press 'Right'. You will see Class A to D. Press 'X' ONCE and press right to the Tutorial. Go through the whole tutorial. Once you are done, you initiated the bug/glitch. You should now see Class E to H for Class 4. Don't get out of the menu, it would disappear and go back to normal. If you learn any of these skills, you will get to keep them. From Class E to H, you will need 450 Class Points. But within each, you need zero Skill Points to learn all. Class G and H got nothing but you can still pretend to learn 'nothing'. Class F has 3 Erde Kasier Retsu/Extreme moves, one deals with slash damage to all, another one deals pierce damage to all and the last one deals thunder damage to all. All need 50 EP. For Class E, you have swimsuit skills and 3 more Erder Kasier moves, Erde Storm, Erde Beam and Erde Quake. For those without the Episode I clear data, this is helpful for you to get Ziggy and KOS-MOS' swim suit skills since they aren't found in the game of Xenosaga Episode II. And do remember these are Class Level 4 skills, you need to pass to Class Level 4 first.