I bought a cheap kilt through e-bay some time ago and found it was too big. I undid the pleats centre back, reduced the waist by 2-3 inches, tucked the surplus material in as a single extra-deep pleat, sewed it all up and pressed the pleats. The sett pattern no longer appears perfect but it is still regular and symmetrical, and it looks fine.

I was tempted to do the same with a good wool kilt too, but have not had the courage to undo it because the pleats are deeper, each one overlapping several others. It would involve so many pleats and the belt loops too, that sewing up again would probably be too difficult.

Martin