Remember you can make this as easy or as difficult as you want. Think about pushing yourself to move through the exercises quickly with no break in between. Give yourself a time limit and see how many times you can get through the circuit (maybe 20 minutes?). The next time you do the workout, see if you can beat your old number.
Also, I'm hoping you have some weights that are substantial. If you have been using 3 lb dumbbells for the past 10 years, it's time to increase your weight! You have my word that you will NOT get "bulky" if you use 10, 15 or even 20 lb dumbbells. Once you have completed the workout, let me know!