You can try hanging it in the bathroom and taking a long, very hot shower (you did get a proper kilt hanger, didn't you?).

You can iron it. NEVER IRON IT DIRECTLY; USE A TEA TOWEL!
Lay it out smooth, spray the crease with water, lay the tea towel over it, and press with the iron (SWK's are polyester; my iron sets to "Acrylic"). If it's over pleats, pick the iron up and put it down; don't drag it over the tea cloth or it might rearrange the pleats underneath.