M2 skin refinish and differin, obagi for acne

Question: I'm 30 years old woman having cystic acne skin. For morning routine, I'm using Obagi clenziderm cleanser, toner and cetaphil lotion. In the evening, I use Obagi clenziderm cleanser, cetaphil moisturizer and Differin 0.1% cream. All the products I'm using is really working well (90% of cystic acne gone) but I want to add M2 skin refinish serum for my hyperpigmentation and acne scars. Could you tell me which step I can apply this serum to get the most effect on my acne scar? Thank you.

You can add the serum to the night portion of your skin care regimen. This way you’re getting the most out of your products because of how your skin regenerates at night.