A step by Step Solution of Rubik's "Magic Cube"
7. Put U corners in place. (contents)
7.d. In one case out of twelve, there will be no U corners correctly placed, and the two diagonal pairs of corners want to be exchanged, as shown. (hide)
Apply R'B2·FRF'R'·FRF'R'·FRF'R'·B2R.