Jenkins is running on GKE as workload and after an update to few plugin and restart, it doesnt start back up. There is no backup or earlier state to restore.

How do we debug Jenkins that is running on GKE? How can I restore and bring it back to an older state? Below is the error and it list so many plugins.

Error 1: The error says install a particular higher version, but I am not sure how to install plugins while its running on GKE and UI is not available ?

SEVERE jenkins.InitReactorRunner$1#onTaskFailed: Failed Loading plugin PLUGIN_NAME. Screenshot showing JUnit

Error 2: com.thoughtworks.xstream.mapper.CannotResolveClassException: org.jenkinsci.plugins.GithubSecurityRealm SEVERE hudson.util.BootFailure#publish: Failed to initialize Jenkins