Parity: swap the right wings
Step 1 / 12
l': Left inner layer: turn 90°, front face goes up (Written as TL' in the textbook)
On both edges, the left wing matches and the right wing belongs to the other edge.
The last two edges at the front and back of the top.
Step 1 of 12: l'. Left inner layer: turn 90°, front face goes up