First you'll want to remove the extra piece from your sewing machine if possible. The smaller the jeans, the harder it is to get in the leg and move and turn as you need to.
Next, you'll want to cut all the strings that are hanging in or around the hole.
Now, measure the size of the hole, so you'll know how big of a patch to cut. I like to allow myself about 1/2" on each side of the hole.
So for this hole, I would cut a 4" X 2" patch.
Cut out your patch. Turn the jeans inside out, and pin the patch over the hole.