Update "Deleting an extension"

docs/Tasks/uninstall-an-extension.md

@@ -1,14 +1,44 @@
-Uninstalling an extension is as simple as deleting an existing ClusterExtension CR: 
-
-```bash
-$ kubectl get clusterextensions
-NAME                          AGE
-operatorhubio-argocd-operator   53s
-
-$ kubectl delete clusterextension argocd-operator 
-clusterextension.olm.operatorframework.io "argocd-operator" deleted
-$ kubectl get namespaces | grep argocd
-$
-$ kubectl get crds | grep argocd-operator 
-$
-```
+# Deleting an extension
+
+You can uninstall a Kubernetes extension and its associated custom resource definitions (CRD) by deleting the extension's custom resource (CR).
+
+## Prerequisites
+
+* You have an extension installed.
+
+## Procedure
+
+* Delete the extension's CR:
+
+    ``` terminal
+    $ kubectl delete clusterextensions <extension_name>
+    ```
+
+    `extension_name`
+    : Specifies the name defined in the `metadata.name` field of the extension's CR.
+
+    ``` text title="Example output"
+    clusterextension.olm.operatorframework.io "argocd-operator" deleted
+    ```
+
+### Verification
+
+1. Verify that the Kubernetes extension is deleted:
+
+    ``` terminal
+    $ kubectl get clusterextension.olm.operatorframework.io
+    ```
+
+    ``` text title="Example output"
+    No resources found
+    ```
+
+2. Verify that the extension's system namespace is deleted:
+
+    ``` terminal
+    $ kubectl get ns <extension_name>-system
+    ```
+
+    ``` text title="Example output"
+    Error from server (NotFound): namespaces "argo-operator-system" not found
+    ```