So I cut them off just above the leg seam.
Then I used the serger stitch on my machine to give a slightly ruffled look to the hem. An overlocker would be better for this, and the funny thing is I do have one. I'm just suffering from overlocker fear. Threading that thing makes me want to break into a cold sweat.
Speaking of unwanted clothing, I also had two tops from my pregnancy that never fit very well anyway. So I modified the pants pattern from Simple Sewing for baby, making them more into a roomy legging style, leaving the bottom hems on the tops to become the hem on the baby pants.
Four very quick new-from-old wardrobe additions.