Turn jeans inside out and unpick the OUTER seam about 8-10" (go ahead and give yourself plenty of room to work, as it's easy to sew up. (The inner seam is usually topstitched, making it a hassle to work with.)
Using your PAPER scissors, cut out a piece of adhesive lined paper to match your patch(es).
With the adhesive (rough) side facing the wrong side of the patch, iron over the paper.
Allow to cool. Peel off paper.
Place patch where desired and iron until adhesive melts to denim.
Proceed to satin stitch (I used a width of 3) around the edge of the patch(es), making sure you keep the seam allowance clear of your stitching! Turn jeans inside out to sew the outer seam you opened.
Or, you could just let your kid wear hole-y jeans.
It's not the worst thing in the world.
PS Should I skip all the how-to photos and go straight to before and after with these kinds of projects?