Enabling Kubernetes PodPresets with kops

I've got a kubernetes cluster which was set up with kops with 1.5, and then upgraded to 1.6.2. I'm trying to use PodPresets. The docs state the following requirements:

1. You have enabled the api type settings.k8s.io/v1alpha1/podpreset
2. You have enabled the admission controller PodPreset
3. You have defined your pod presets

I'm seeing that for 1.6.x, the first is taken care of (how can I verify?). How can I apply the second? I can see that there are three kube-apiserver-* pods running in the cluster (I imagine it's for the 3 azs). I guess I can edit their yaml config from kubernetes dashboard and add PodPreset to the admission-control string. But is there a better way to achieve this?