Access with system:admin in OCP 3

Issue

• ~.kube/config file was corrupted or deleted on my master.
• How can I log in as system:admin from a remote system?
• How can I rebuild ~/.kube/config file with system:admin certificate data?

• While trying to login as "system:admin" user to OpenShift Container Platform terminal fails with error:

  # oc login -u "system:admin"
  Authentication required for https://master.example.com:8443 (openshift)
  Username: system:admin
  Password: 
  error: username system:admin is invalid for basic auth