Go to the invitation to a party level, then go behind the dumpster near the street. There you will see a box that looks like the same box in your garden shed. Pick up the poison then go inside the mansion where the garage is. (You have to have a waiters uniform.)Make sure you walk normal past the guards in the garage. All the gaurds will do is yell at you. Don't shoot. Finally go down the hallway and you will find a door that leads to the kitchen where the chef is. Pick up the champagne glass thats on the counter. go to the room behind you and make sure the door is closed. Push Y to get the inventory list and select the poison. Push b then push y again. Select the champagne glass. The character will put the poision in the glass. Go into the ballroom and wait for the general to come out the door on the left. Walk up to him and he will take the champagne glass. Follow him and he will be in the bathroom over the toliet throwing up. Wait there for a few seconds and he will die.