I hemmed a kilt of lesser yardage once. It was 24" length and I wear a 22.5" length. It was not hard just time consuming. Although, repressing the ends of the pleats was a pain in the _ _ _ ! They didn't come out right.

I suggest either leaving it at 24" length and just wearing it with a higher rise (like a military kilt) or not getting one at all. Just get a kilt in the length you require.

The problem with hemming a pre-made tartan kilt is, the centered display of the tartan in the front apron... might not look right after being hemmed or might not look as good.

This is just my opinion...