What you need:
Clown Trousers (must be baggy in the legs, light flowy fabric with a busy pattern, but a good fit on the waist)
3. Take a straight edge (honest no measuring) and draw a straight line in pen/chalk, from just above the crotch part (the weird triangle shape in the photo) it doesn't need to come to a point at your hem just a few inches up is fine. Repeat this for the other side.
4. Cut this part off and repeat for the other side, see it's already looking like a skirt, excuse the double vision!
5. Take the trouser/skirt hybrid to the sewing machine (I used my serger here but a sewing machine is equally good) and sew up the sides you've just cut. To make things easy start with the side with the back label on, then you'll know you are sewing the right pieces together. Repeat this for the other side.
Skirt all sewn up
How it will look inside out (this is the back of the skirt facing you), notice that you've made a new seam down the middle of the back of the skirt? well you made one at the front too. If you had a plain skirt then this would be more noticeable but this busy print and pleats at the front completely disguise this skirts humble beginnings.
Now this skirt would be too long for me and yes I know that longer hemlines are back but I can't pull them off so I chopped off the skirt to knee length then hemmed it.
If you're looking for a long skirt and the new skirt is the right length then you just keep it as is, you won't even need to hem it. Magic!
As usual the final and most important step is to send me a lovely message of thanks, and/or flowers (Lilies) or Belgian Chocolates, what can I say I have expensive tastes in gifts if not in clothing :)