Last two centers: two pieces below
Step 1 / 4
D': Bottom face: turn 90°, front face goes left
The top has one pair; the other two pieces sit side by side on the bottom.
D' moves the bottom pair left, Rw2 lowers the elevator, D2 moves the pair right, Rw2 lifts it.
Step 1 of 4: D'. Bottom face: turn 90°, front face goes left