If you are not familiar with the oc command, refer to OpenShift - Getting Started with the oc command.

Before you can use the oc projects command, you must first login using the oc login command. 

Before deleting a project, you'll probably want to use the oc get projects command to list the available and currently selected project. Let's say the oc get projects command returns the following, which indicates that project2 is the currently selected project.

oc get projects

You have access to the following projects and can switch between them with 'oc project <projectname>':

   project1
 * project2
   project3
   et cetera

Using project "project2" on server "https://api.openshift.example.com:6443".

The oc delete project command can be used to delete a project. In this example, project3 will be deleted.

oc delete project project3

Something like this should be displayed.

project.project.openshift.io "project3" deleted