Update the cron LCFG module to call the script:
${EDG_LOCATION}/etc/cron/edg-java-security-container-proxy-renew-cron
The suggested interval is every 12 hours.
Note that the cron interval, proxy lifetime and SECURITY.PROXY.UPDATE.INTERVAL depend on eachother. In the defaul installation everything is OK, but if changing the defaults can bring problems. Obviously proxy lifetime has to be longer than the cron frequency to prevent the proxy from expiring before it gets updated. But, the SECURITY.PROXY.UPDATE.INTERVAL which defines how ofter the tomcat reloads the service proxy has to be less than (proxy lifetime)-(cron interval).