Ham ’em High level 12-5 is a bit challenging. One strategy is to fire Big Brother through the top half of the first wooden wheel. This will reduce the vehicle to rubble. Launch the first Yellow bird below the larger pig in the middle of the structure. If the TNT on the extreme right does not detonate, snipe it with the last Yellow bird. The score in the video below is 79,690.
Method #2 results in a lower score — 76,590 — but uses only two birds. Launch Big Brother just above the larger pig in the middle of the structure. The larger impact should detonate the TNT on the extreme right. Then fire the Yellow bird through the small wooden square above the first wooden wheel.