Let me start from the beginning.

1) Get into random encounters in the grassy area around the Chocobo Stable.

2) One of the random monsters you encounter are small squirrel-like monster called a Muu (sp?). One of their attacks is a learnable Enemy Skill called Level 4 Suicide. I'm pretty sure you can manipulate them into casting it. It does critical damage to anything with a level that is a multiple of 4 (4, 8, 12, etc...).

3) If a character with E-Skill materia gets hit with Level 4 suicide, he or she will learn it.

4) You can learn a different Enemy skill, Chocobuckle, by finding a chocobo that has a level that's a multiple of 4 (so it's vulnerable to Level 4 Suicide). You can find chocobos like this in the area around Mideel.

6) Get into a random encounter with monsters and a chocobo (so you'll need to equip Chocobo Lure materia and run on the chocobo scratches). You may have to kill all the monsters except for one and the chocobo before going to the next step.

5) Throw a Mimett Green to the chocobo and cast Level 4 Suicide. The chocobo should counterattack the caster with Chocobuckle.

That should be it! You now should have two additional Enemy skills in your posession.