Slice the centers back into alignment. Repeat this until the top and bottom layers are entirely filled with completed 5-piece edges. Step 2: The Last Four Edges (L4E)

The last two centers will always be the most difficult because you have no "free" faces left to safely move pieces. You must rely on short commutator algorithms (like Rw U Rw' variations) to swap final misplaced center pieces. Phase 2: Pairing the Edges (Freeslice Method)

This algorithm flips the edge piece located at the Front-Right position. 7x7 Parity Issues

[3] Rokicki, T., et al. (2014). "The diameter of the Rubik's cube group is twenty". SIAM Review , 56(4), 645-670.

From here, use standard (Cross, F2L, OLL, PLL) or the Layer-by-Layer beginner method to finish the puzzle. 4. Overcoming 7x7 Parity Errors