First thing to say it.... be very careful about ironing a kilt.
You might find that hanging it up for a few days will remove the creases, perahps hanging it for a while in a slightly steamy area, like a bathroom might help.
Pressing a wool kilt needs a pressing cloth, and lots of steam,the iron can be failry hot, but must not touch the kilt except through the cloth.If the basting is still in the kilt then the pressing will be easier.Pressing is the idea ,rather than ironing, so press the iron down , lift up and down again, and again ,and avoid moving it all over .