Today I found a nice command, namely zoneadm apply. With this command you can alter the configuration from a running zone.
Some Oracle guides instruct to use: zonecfg -z "zone" -r but as alternative you can also use zonecfg -z "zone", change desired items and afterwards apply them with zoneadm -z "zone" apply
Reference:
http://docs.oracle.com/cd/E36784_01/html/E37628/gogja.html#scrolltoc