Revert back CRD settings

content/rancher/v2.x/en/installation/other-installation-methods/air-gap/install-rancher/_index.md

@@ -184,14 +184,18 @@ If you are using self-signed certificates, install cert-manager:
 kubectl create namespace cert-manager
 ```
 
-1. Launch cert-manager.
+1. Create the cert-manager CustomResourceDefinitions (CRDs).
 ```plain
-kubectl apply -R -f ./cert-manager
+kubectl apply -f cert-manager/cert-manager-crd.yaml
 ```
 
     > **Note:**
     > If you are running Kubernetes v1.15 or below, you will need to add the `--validate=false` flag to your `kubectl apply` command above, or else you will receive a validation error relating to the `x-kubernetes-preserve-unknown-fields` field in cert-manager’s CustomResourceDefinition resources. This is a benign error and occurs due to the way kubectl performs resource validation.
 
+1. Launch cert-manager.
+```plain
+kubectl apply -R -f ./cert-manager
+```
 
 {{% /accordion %}}