A pretty simple grenade. It has absolutely no script; it is comprised entirely of mechanics.
It has a lock on it. The lock is irreversible, once the grenade is unlocked, you cannot re-lock it. This lock is located on the top of the Grenade. Spin it Counter-Clockwise until the indicator turns red.
The Indicator will turn red once the pin is able to be released from the grenade. It begins as green and can be found directly underneath the entry point of the pin into the grenade.
Once the lock is undone, you may pull out the pin. The handle will 'eject' and the grenade will explode. IF the handle does not have room to eject freely, the grenade will not explode, like on a real grenade.
Before you unlock the grenade, it is extremely hard to set off. You may toss it, throw it against the wall, or beat it with another block and it will not explode. This is what makes the grenade amazing, for it's such a simple design, but without a script.
Keep in mind that if you DO crush it, it WILL explode!
That will be all! You may use the design if you'd like!
Have PHUN!
EDIT - I have created images for people who may want to see the grenade explode before they download it.
http://i56.tinypic.com/5uo8xl.jpg
http://i56.tinypic.com/2cf34ew.jpg