Spray it with a decent rose and flower spray. Ortho, Bayer for example. Follow label directions.

And if you'd like to avoid the insecticides, the easy, safe, cheap alternative is putting affected pots in a tall plastic container, overfilled with water, for a couple days. The aphids drown and float. The plants look like "drowned rats" for a week or so but grow new leaves. I am 4 for 4 with this approach. Life goes on!