Hey Mikeyw8187,
I had some problems with this mission myself and Gideon gave me the best help...
What you do is take 8 ball down to the boat and let him get out and run to his hiding place. Then what you do is drive around the building to the front close to where you came in. There are some shipping container inside the gate to your right and go to them and get out and look around them... you will find a pill next to couple of containers, take it and run
*back down to where you left 8ball and get up on the roof. You should have plenty of time to pick all the columbians off!!
Remember after you take the pill don't get in you car or it will wear off, just run back down there!
Hope this helps you :2devilish: