STEP1. Top corners.

Permute top corenrs as same as 3x3x3.

(You can solve all corners first. Then, you can follow the next steps.)

STEP2. Middle edges.

2 Pairing & Positioning

 I usually make pair of middle edges in first, then position it one pair by one. If the edges locate, in U or D layer, it is easy to make pair.

ex.

-> D2r2 -> -> (l'r)F'(lr')F -> -> (l'rR)F(lr')F'R' ->