Center 1: one corner on the opposite face
Step 1 / 8
x': Whole cube: turn 90°, front face goes down
The top is missing only the back right corner spot of its center. The white piece sits on the bottom, right below the gap.
x' brings white to the front. Same pattern as One corner piece in Last two centers, with r2 for r and B for U.
Step 1 of 8: x'. Whole cube: turn 90°, front face goes down