Centres and edges
Reduce it to a megaminx, then use the megaminx's sets.
The gigaminx, teraminx, petaminx, examinx, zettaminx and yottaminx are megaminxes with more layers per face, as the 4x4 to 7x7 are to the 3x3. They are solved by reduction: build each face's centre, group each edge's pieces, then solve the result with megaminx steps and algorithms (wide turns move the inner layers with the face).
Notation follows big cubes: R turns the outer layer, 2R the second layer alone, Rw (or r) the outer layer and the next, 3Rw the outer three.
A gigaminx after a wide turn and a face turn.
Rw U
The yottaminx's top face and the pieces beside it.