Go up to the obelisk or wherever you can pick up an item, push X(I think) to change to give item and pick a grenade, a walkthrough said to use a Plasma Grenade but I found the Frags worked just find.
This belongs in the KOTOR forums.
Remember the breeze across your face
Remember the swaying sleeves in the wind
Remember the grains of sand beneath your feet
between your toes
Remember the freedom in the never ending waves
Remember I'll be at the beach.
Jedi Academy - Renaissance