I shot the first bird just over the light pole so he's coming in right at the top left corner of the middle wooden section. Drop the bomb just before he hits and you'll take out the first two sections of glass in the middle and he'll take out the top wooden structure, maybe a little more.
Second bird (big guy) I shot pretty much square at the light pole. He'll take out the light pole and enough of room to let the second bomb bird get in low towards the middle
Second bomber bird - The goal is to clear the middle, center snow section to make way for the streaking bird to make it low into the back lower wooden sections.
Streaking bird - You want him to come in low and straight at the lowest pig. If everything lines up correctly the top sections will tumble left and take out any of the pigs you might have left remaining.