You will need to access the instance using a SSH connection
Then, this command will print the list of plugins
/opt/bitnami/apps/wordpress/bin/wp plugin list
If you want to disable one, just run this command
/opt/bitnami/apps/wordpress/bin/wp plugin deactivate NAME_OF_THE_PLUGIN_HERE
However, I think the other guide will be more useful for you. If you remove the malware code from the application, you will probably regain access to the site. You will need to access the instance using SSH and then modify the WordPress files you can find inside the /opt/bitnami/apps/wordpress/htdocs.