Ok you get a car of some sort, any one really and park to the side of the package (the one without the big drop). and carefully jump down onto the little ledge to get that package. The second package on bridge you have to wait till you pass some missions and then a bridge and construction material should appear, there is a ramp then and you jump over it on a mission to get to the second island, just get out your car then and get the package.
Does that make sense? :S
Eminem: The Legend of Legends