4x4x4 to 3x3x3 Reduction Method

Pulling edges together

If edges can slide together: d R U R' d'

If edges oppose each other: d R F' U R' F d'

Final parity

Opposite edges need to be swapped:

r'2 U2 r'2 Uw2 r'2 u2

One pair of edge pieces need to be inverted:

r' U2 l F2 l' F2 r2 U2 r U2 r' U2 F2 r2 F2

5x5x5 Algorithms

Last 2 edges

Swap opposite center edge pieces:

Rw2 F2 U2 r2 U2 F2 Rw2 (Rw2 is R three slices)