Step Four: Corners of the Last Layer
At this stage, the only pieces left to solve are the corners of the last layer.
If you look at the D layer, you'll notice that all the corners are permuted, but they may not be oriented. Or, you could be the lucky 11.11% and have a solved Skewb. If so, congratulations! For the other 88.89% of us, we are equally likely to have either of two unsolved cases.
Peanut 2 corners 
(F' R F R')*2 y (F' R F R')*2
y2 F R L' B' y' R F' L' y' R L R' (optimal) 

Pi 4 corners 
(F' R F R')*2 

It should be noted that for Peanut, the Dface stickers should be visible as pictured before executing the corresponding algorithm. For Pi, rotate the puzzle so that there are two Dface stickers on the B face before executing the corresponding algorithm.
After this, your Skewb should be solved! Hooray!