Prometheus configuration file with TLS support

prometheus.yml

# my global config
global:
  scrape_interval: 15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: 'prometheus'
    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.
    static_configs:
    - targets: ['localhost:9090']

  - job_name: 'nodes'
    scheme: https
    tls_config:
      cert_file: '/etc/prometheus/client.crt'
      key_file: '/etc/prometheus/client.key'
      ca_file: '/etc/prometheus/root_ca.crt'
    file_sd_configs:
    - files:
      - 'targets/nodes.json'

Hi I have already TLS enabled with the help of your above code , now i need to renew a signed certificate . Can you let me know the steps and configuration for the Cert renewal .