This glitch lets you equip any armor no matter what class you are. This glitch even lets you equip alien armor.

1. Go to your Armor list.
2. Locate the Armor you want to wear.
3. From the bottom of the list, count up to your Armor. Remember the number.
4. Press X to go to your Upgrades.
5. This is the tricky part, from here press Y and quickly press A (right when you press Y, press and hold A like a millisecond later. The screen will show lots of weird slots on top if done right).
6. You'll get the "turn into omni-gel" screen, but get taken back to the armor list.
7. Choose No to remove the screen and go all the way to the bottom of the list.
8. From the bottom, count up to where your Armor would be.
9. Equip, then choose Yes.
10. Done!