Move 1 in detail

Shown below are figures to help you visualize what the steps of Move 1 involve.

Move 1: U-1 F U L-1   U L U-1 F2
Figure 2a  Figure 2b 
U-1: Rotate the top counterclockwise F: Rotate the front clockwise
Figure 2c  Figure 2d 
U: Rotate the top clockwise L-1: Rotate the left side counterclockwise
Figure 2e  Figure 2f 
U: Rotate the top clockwise L: Rotate the left side clockwise
Figure 2g  Figure 2h 
U-1: Rotate the top counterclockwise F2: Rotate the front clockwise twice
Figure 2i 
The move is complete, and has swapped the bottom-front corner pieces.
Notice that it also changed the orientation of the top-front corner pieces, 
but they are still in the correct location. We'll fix their orientation in Step 3. 

Continue step 2