Unless you want to trim your armor, i suggest something i tried with my armor; just take some foam and glue it to the insides of your thighs so they don't shake around and will stay in place. Otherwise you'll have to deal with the 'clankyness' of your armor moving on you. As for the elastic, you may have to trim and sew in order to preserve what you need and remove what you don't want. Other than that, it seems to fit you well!
+1 for using Imgur